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Answering Two Objections to Aquinas

Aquinas2

I'd like to share an excerpt from my new book Answering Atheism, which answers two common objections to Thomas Aquinas’s first way of proving the existence of God. This way is usually called the argument from motion.

Objection #1: What moved God?

 
The “new atheists,” like Richard Dawkins, sometimes make a caricature of Aquinas and claim he is arguing that, “Everything needs a cause. Therefore, there had to be a first cause called God. God is the exception and has no cause of his own.”1 But Aquinas never makes such a simplistic argument.

He says that everything in motion only moves because it has a potential to move. Since nothing can move itself, an object can only move if its potential to move is activated by something outside of it. For example, water has the potential to freeze if the air temperature lowers enough to act upon the water and freeze it. But water can’t just turn into ice by itself. Likewise, the air that freezes water has a potential to become colder if something else acts upon it (like changes in air pressure).

But what makes God different from anything else is that he has no potential to move or change. God is pure motion itself (or what Aquinas calls act). Nothing changes God in order to bring about effects in the world. Instead, God brings about effects by his own power. God can act on his own because, once again, there is nothing potential about God.

Aquinas is not saying everything has a cause except for God, as if God were one object among many in the universe. Instead, he logically arrives at the conclusion that since all things have potential in them and musty be moved by another there must be something which has no potential that moves everything. God is not an “exception to the rule,” he’s an entirely different “rule” or kind of being.

This refutes Dawkins’s claim that there is no good reason to say God does not require a mover of his own. Asking the question, “If everything needs to be moved, then what moved God?” is like asking the question, “If every car on a train needs to be pulled, then what is pulling the locomotive?” It is because God is not acted upon by anything else that he is able to be pure being itself and cause everything else to exist and move in the world.

Objection #2: Why not an infinite number of movers?

 
Another popular objection goes like this: “Aquinas begs the question when he says that there cannot be an infinite number of movers and so there must be an unmoved mover that sets everything in motion. But why can’t there just be movers or causes going back infinitely in time?2

To this objection Aquinas makes a distinction between causes that are sequential and causes that are simultaneous.3 Sequential causation is like a chain of dominoes. After you knock over the first domino you start a chain reaction of dominoes hitting other dominoes. In fact, you could destroy the first domino after you’ve pushed it since it is no longer needed to keep the whole set of dominoes falling. Aquinas believed that sequential causes in the past, like a set of dominoes, could have occurred for all eternity.4

Aquinas argues that God explains the existence of simultaneous causation. An example of this kind of causation would be a golfer hitting a golf ball. The act of the golfer hitting the ball is not as simple as we might think. The golf ball is moved by the golf clubhead, but the clubhead is simultaneously moved by the swing of the shaft, which is moved from the handle, and the handle is simultaneously moved by the flexing of the golfer’s muscles, which cannot flex without nerve signals from the golfer’s brain stimulating them, and so on and so on.

Aquinas argues that such a chain of causes cannot be infinite because the causation is all happening at the same time. This is like a train with an infinite number of boxcars that are all moving at the same time. In that case, there has to be an unmoved mover (the locomotive) that causes all the simultaneous motion to occur at all. Likewise, there must be an “uncaused cause” that sustains the elaborate chain of simultaneous causes in our universe. We call this uncaused cause God.

Even though Aquinas’s arguments are very powerful, we must be careful when using or attempting to refute them because they are easily misunderstood. The philosopher Edward Feser has written in his excellent book Aquinas that the five ways are only summaries that were originally written for beginning theology students. Feser says that:
 

"Aquinas never intended them to stand alone, and would probably have reacted with horror if told that future generations of students would be studying them in isolation, removed from their original immediate context in the Summa Theologica and the larger context of his work as a whole."5

 
A careful student of Aquinas will also see that his arguments only make sense if you understand all the terms he uses, such as “act” and “potency” and different types of “causes.” This doesn’t make them bad arguments; they just require more understanding in order to be adequately communicated to a non-believer. For those who are interested in truly understanding these arguments in depth, I recommend Feser’s book Aquinas: A Beginner’s Guide.
 
 
Originally appeared on the Catholic Answers Blog. Used with permission.
 

Notes:

  1. A paraphrase of Dawkins’ objection found in The God Delusion (Houghton Mifflin Company, New York: 2006), 101.
  2. Michael Martin, Atheism: A Philosophical Justification (Temple University Press, Philadelphia, 1990), 99.
  3. The formal terms are per se causation (simultaneous causation) and per accidens (sequential) causation. See Feser 69-70.
  4. See Fr. Robert Spitzer, New Proofs for the Existence of God: Contributions of Contemporary Physics and Philosophy (Wm. B. Eerdmans, Grand Rapids, 2010), 177-180.
  5. Edward Feser, Aquinas: A Beginner’s Guide (OneWorld, Oxford, 2009), 62-63.
Trent Horn

Written by

Trent Horn holds a Master’s degree in Theology from the Franciscan University of Steubenville and is currently an apologist and speaker for Catholic Answers. He specializes in training pro-lifers to intelligently and compassionately engage pro-choice advocates in genuine dialogue. He recently released his first book, titled Answering Atheism: How to Make the Case for God with Logic and Charity. Follow Trent at his blog, TrentHorn.com.

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  • DAVID

    The explanation of objection #2 is good. The analogy of a locomotive engine pulling the boxcars is useful. But I would really like to read the whole argument, fully laid out, as to why a simultaneous causal series cannot extend infinitely. Anyone know where I can find this?

  • Trent is wrong about water, it is the other way around, ice needs heat to give its molecules more energy, when this happens it melts. There is no such things as cold, rather different level of heat. But the idea still works.

    • geekborj

      I think what he meant was that water has the potential to be devoid of heat (specifically, random motion of its molecules; or generally devoid of energy). The act of being frozen (being devoid of energy, thus frozen as its external manifestation or effect) cannot be without any act of an external agent such as the atmosphere, the freezer or a container that changes the pressure of the liquid water.

      In any case, I agree that the idea still works if we see "coldness". It's just not measured in real physical experiments. Its more plausible that "heat" is the one present and coldness is rather defined relative to it: coldness is absence of heat, as darkness is absence of light rather than presence of dark.

      • Wow, this is a blast from the past!

        I do not think water can be devoid of heat and still be water. Being frozen is by no means being devoid of energy. Ice has lots of energy.

        Coldness cannot be measured, heat can. "cold" is a label we apply to things that lack the heat we might expect or which drain heat from ourselves and so on.

        Water can and will indeed turn into ice if left alone.

        • geekborj

          In physics, this is theoretically possible and there are already substances that has been brought very low in the order of 10^(-15) degrees Kelvin, that's very close to absolute zero. At absolute zero, it is believed that all motion ceases (devoid of energy, besides the rest mass energy of course).

          If water is left alone (as "closed system" in physics), there is no exchange in energy with surroundings and it will never become ice if left alone like that. It has to interact with the environment or an "external agent".

          • I utterly disagree.

          • geekborj

            Of course, it is still the water substance in a different phase -- that is solid phase, if that's what you mean that it is "still water." The main points are: (1) it is theoretically possible to imagine a system without any thermal energy in them; (2) removing thermal energy in things results to phase changes (e.g. solidification), in water, it becomes ice; (3) any closed system will never lose energy by virtue of the definition being "closed", thus, left alone, water cannot turn into ice without being in contact with a surrounding with low temperature.

            Which of these you don't agree?

  • Sorry, there is no refutation of objection number one. The objection is that Aquinas has developed a rule through observation, everything we see in motion appears to have a cause for its motion. Then he says there exists something in motion without a cause for its motion. If he is simply positing some idea of a way of being that is pure motion and is immune to his identified rule, fine. But what then is the relevance of this rule to the god in the first place? If there is a relationship, then the god is an exception. You cannot have it both ways.

    • Ben Posin

      Someone once put this more eloquently on this board than I can, but basically Trent/Aquinas, despite Trent's protests, is trying to define his God into existence through special pleading. Neither Trent or Aquinas has ever encountered anything in reality that has "no potential" (as he puts it}, and doesn't know what such a thing would be like or how it could exist. But he wants there to be such a thing, so he's perfectly content to throw these nonsense labels on a mystery box, and then tell us that by definition there must be something inside.

      I can you tell you that this article really lessens my desire to read Aquinas. Doing so hasn't done Trent any favors.

      • Caleb Cumberland

        But he is arguing that of course we haven't found anything that lacks potential, in the natural world, because then that thing would be God. But if it is logically necessary that there is such a thing, so that other things can actualize, then it follows that there must be such a thing, even if that thing is disanalogous to what we find in the natural world.

      • Irenist

        I'm not sure how it's special pleading, Ben.

        If the argument satisfactorily demonstrates that there must be a Pure Act in order for any simultaneous (per se) series of changes from potential to actual to exist, and thus for anything to exist AND we observe that something (even if it's just our own thoughts) exists right now, then there must be a Pure Act. Further argument then follows to demonstrate that Pure Act is the Being we call God, with all the standard attributes.

        But we DO observe that there is something rather than nothing. So either the argument is cogent or not, but I don't see how it's special pleading.

      • geekborj

        The idea that since one has "not encountered" something does not mean we ignore it as if we does not know such. For example, before the Higgs boson was "discovered" via series of experiments using the Large Hadron Collider, it was actually "predicted" via argumentation such including mathematical reasoning. We have not initial encountered Higgs boson before we said it existed.

        Thus, one cannot dismiss the existence of God based on argumentation and intellectual "thought experiments" and rely totally on "ever encountering such". Einstein and his colleagues will have to disagree on the validity of "thought experiments" in knowing possibilities such as black holes and the like ... even time-space warping as the cause of gravity.

    • Andrej Tokarčík

      Hi Brian. The principle held by Aquinas is not that everything in motion has a cause for its motion. Rather, the relevant ontological principle that he adheres to says that everything that is moved is moved by another, or put more formally, that everything that is in potency is raised to act only by something that is in act.

      As I understand Your post, You're making the common mistake of reading the universal principle as a variant of "everything that exists has a cause", which is really absurd if a being without a cause is supposed to exist, as You rightly point out. Aquinas, however, doesn't make such an assumption, his principle would instead analogically read as "everything that begins to exist has a cause", which doesn't result in a logical inconsistency when admitting an uncaused being.

      Cheers,
      Andrej

      • Does Aquinas only some things in motion have an external cause for their motion or not?

        Isn't this pretty much resolved by Newton's first law?

        • Andrej Tokarčík

          Hi, I just realised I replied too hastily to Your first comment: Your initial formulation along the lines of "everything that is in motion has a cause" was actually correct. I had seen a difference between Your and my way of putting it because I had thought that the category of things in motion includes both things being moved and things causing motion in others. Now, THAT is incorrect. The things in motion are apparently only those that are being moved. I'm sorry for the confusion.

          Still, Your previous comment wasn't entirely precise, but it seems to be so due to one dubious formulation from the article, specifically:

          God is pure motion itself (or what Aquinas calls act).

          It can be me and my background once again, but to my knowledge Aquinas certainly does not consider act and motion to be the same. It suffices to take a look at the definition of motion (below, taken from the summary of the First Way, Summa Theologica) to see that the terms cannot possibly refer to the same concept (except in a very metaphorical manner):

          For motion is nothing else than the reduction of something from potentiality to actuality.

          Thus, it must be said that the First Way does establish, if successful, the reality of Pure Act, not pure motion. Indeed, given the definition of motion, pure motion seems to be a non-sensical concept.

          Now, unsurprisingly, that led to a mistake in Your own thinking:

          Then he [Aquinas] says there exists something in motion without a cause for its motion.

          The Pure Act is not moved -- because if it was, then by definition of motion, it would imply that it had some potentiality that could have been actualized in the first place, which is in contradiction with its being the Pure Act (the Pure Act is not potential in any way). The Pure Act is not moved, but still it moves others, i.e. it actualizes potentiality of other things.

          Hope it's clearer now,
          Andrej

          • What you and Aquinas appear to be doing is identifying concepts, like "motion" or as I've seen elsewhere, "being", and labelling these as "god", as if the essence or perfection of these concepts needs must exist in some way.

            This philosophy of believing abstract categories have some way of existing beyond our brains is understandable for the kind of Platonic philosophy in which I understand early Christianities arose. I don't accept that "motion itself" is anything more than a concept and doesn't exist in any other sense, I don't see why I should.

          • Andrej Tokarčík

            I tried to clarify myself in the previous comment where I wrote that there is nothing like "motion itself" in Aquinas's philosophy -- it is "act itself", instead. But act is a mode of being and not an abstract concept, so Your objection doesn't seem to hold.

            In fact, Aquinas as well as Aristotle hold to the position of so-called moderate realism, which is in opposition to Plato's absolute realism. Plato believed in the existence of an unchanging world of ideas (or forms, to be more precise); neither Aristotle nor Aquinas did. Aristotle taught that ideas/forms (such as "catness") exist only in real things (instantiated in individual cats) or in the intellect (when grasping the idea of what it means to be a cat). But, and this is important, Aristotle and Aquinas never suppose a priori that abstract ideas/forms alone of themselves exist, unlike Plato.

            Hence, when Aquinas arrives to the existence of Being Itself, Goodness Itself etc., it is always in an a posteriori manner. We analyse the observable phenomena and if it happens that it is necessary to admit the existence of what before appeared to be a perfection/concept, we do, but never elseways. Put simply, the proofs do not pre-suppose that we have to accept the subsistent existence of a perfection/concept just because we are able to think about it.

            (Also, my other comment below may be helpful.)

            Best,
            Andrej

          • Whether you are calling it "motion itself" or "act itself" you are anthropomorphizing a concept into a "being" or a [...] that in some way is independent of the material cosmos.

            I just see no point to this, unless you are committed to making room for some kind of cosmos-creator. We observe matter behaving in certain ways. We develop concepts to understand what we see, from "motion" to "being" to "home" to "sport" and so on. These concepts are fluid and fuzzy but most are generally understandable. They are conceptual abstractions in human brains. I see no reason to think this entails anything non-material, much less a deity.

          • Andrej Tokarčík

            Sorry, but I probably don't understand Your first paragraph. Are we still talking about the First Way? Do You see a problem with that Pure Act can actually exist, or that once established it exists it is said to possess "human-like" properties such as intellect, will, perfect goodness, etc.? I'd rather keep discussing only one of those :)

            Actually, I'm starting to see that You're probably objecting to Aristotle's assumption that the principle of non-contradiction is a law of objective reality and as such the natural order is logical. Because this is how even a non-material being can be "reasoned" into existence. Given that logical reasoning can be used to analyse and predict operation of all natural phenomena, if a sound philosophical argument shows that a non-material being exists, then such a being must exist. This is probably the principle underneath all of it that You're not content to accept. Or is it?

          • Yes I do not know what you mean by either "Pure Act" or "exist" in this context. Do you follow the distinction I am making between concepts and the things the concepts map to? And that just because we develop a concept it does not follow that any entity actually maps to that concept?

            I think you have a concept of Pure Act, but that doesn't mean it exists any more than Pure Apple exists.

            I think it is evident that if Pure Act did exist it could not ever be a human being, then it would no longer be Pure Act, it would be something else.

            If a valid and sou d deductive argument shows that a non-material being exists, I would accept it. I haven't heard one. We would first have to agree on what "exists" means, because I don't think we do. I would say that matter or energy is necessary for something to exist

          • Andrej Tokarčík

            Hello, Brian.

            I think it is evident that if Pure Act did exist it could not ever be
            a human being, then it would no longer be Pure Act, it would be something else.

            Could You please explain why it is necessary to think of Pure Act as a human being, as You seem to be implying?

            But more importantly: saying both that

            If a valid and sou d deductive argument shows that a non-material being exists, I would accept it.

            and that

            matter or energy is necessary for something to exist

            are true is inconsistent. If You assume a priori that matter is necessary for something to exist, then obviously there can be no argument whatsoever that would convince You that a non-material being (that is, a being for which matter is not necessary to exist) exists, not even any valid and sound deductive argument.

            That is, Your axiom of every being's depending upon matter as the being's principle of existence is a total discussion stopper, since even our very basic assumptions* are incompatible, I think that there can be no reasonable exchange of ideas. Now, You're certainly free to hold that "material things are all that exists" as an axiom, but in that case also people who appear to hold that "non-material as well as material things are all that exist" as an axiom are free to do so without any blame.

            At least, that's how I get Your comment. Sorry if I misunderstood and thanks for staying with me,
            Andrej

            _____
            * - Mine being not that "both material and non-material things exist", but simply that "material things exist", which, however, by itself, does not prevent non-material things to exist.

          • You seem to be describing this god as "Pure Act", or vice versa. This website is about the Catholic religion. In that tradition "god" is also a being that became fully human and was killed. I do not see how, even if you could establish that "Pure Act" existed in some way, that this makes it a "god" in the Catholic context. Once it gets human it is more that "Pure Act" if this "Pure Act" is not capable of taking material human form, then there really is no point in referring to it as the Catholic God.

            It is my position that to exist something must either be matter or energy. I can be convinced I am wrong and that non-material existence is possible. A valid and sound deductive argument would convince me. I am not saying that no such argument or evidence could be advanced, I just have not heard any, nor can I conceive of any.

            Materialism is not an axiom of mine. I do not assume existence is a priori material only. I do not even take matter and energy a priori. I observe matter and energy and I believe very strongly that they exist. Matter can be invisible and energy can have no mass, but I think it is nonsense to say something "exists" with neither.

            The only axiom I have, I think, is induction.

          • Andrej Tokarčík

            Hi! I think that on the matter of Incarnation, You're proposing a false dilemma: either any theistic argument given on this website completely proves the Catholic religion, or it is invalid/unsound.

            The argument from motion can be perceived as the first step towards rational justification of the Catholic religion. None the less, the aim of the argument standing alone is to determine the existence of Pure Act, not to fully justify the Catholic religion. If You think that Pure Act cannot become a human being for whatever reason, it has no influence in relation to the validity/soundness of the argument. After all, deductive arguments in general are first and foremost about conclusively revealing some truth, and if the argument's conclusion does not sufficiently imply the truth of the Catholic religion -- even in the context of a website promoting Catholicism -- it doesn't follow that the argument can be dismissed on that ground alone.

            Moreover, a defender of the argument from motion doesn't start with the description of God as Pure Act. Rather, he proceeds from observation of change in the observable world to the existence of Pure Act as the necessary condition of all change, just then to deducing that Pure Act must have divine properties (the argument from motion alone, without further elaboration, does not lead even to this conclusion), and just then eventually to the belief of the divinity of Jesus Christ. (Also note that each of the stages may use different methods to the respective conclusion.) It now may be obvious how the argument from motion can be accepted even without admitting the divinity of Jesus Christ. As for Thomism, it is consistent to adhere to the philosophy while not being a Catholic Christian.

            I'll take Your word for Your openness towards the possibility of the existence of immaterial beings, and I'll try to show that the argument of motion is a valid and sound argument. I shall respond to the points You raised in the previous comment about the merely conceptual nature of the terms employed in the argument, for I don't know about any other objections that You have against the validity and soundness of the argument.

            I think I do understand the distinction You draw between concepts and the things referred to by the concepts. Nonetheless, Aquinas doesn't make his argument in question in order to "develop" a concept, but to establish the existence of a real being instead (or rather, to explain the reality of motion, which ultimately happens to require the existence of a being with such qualities). There are no arguments necessary to set forth a concept.

            Certainly, it cannot be said that Pure Act is not a concept. But the fact that Pure Act is a concept doesn't prevent the thing referred to by the concept from existing. Indeed, Aquinas makes his argument for the existence of the
            being he refers to as Pure Act, precisely because he doesn't think it is self-evident that such a being exists and also because he thinks that beings can be shown to exist without their direct observation via observation of their effects and consequent logical reasoning.

            That is the main point: Aristotle and Aquinas analyse the operation of material things just to realise that material things can undergo change the way they do only if there is an immaterial being that is the ultimate cause/explanation of the manner of change. They reason from the observable effects to the unobservable cause, just like physicists have reasoned the concepts of pure matter and pure energy "into existence". Even though Pure Act is a concept, it doesn't exist just by the virtue of being a concept (as Plato would), but by the necessity implied by the observed effects of which Pure Act is the only possible cause.

            Best,
            Andrej

          • Ok, it just seems to me that the Pure Act being advanced rules out any material reality for Pure Act. But if not, fine.

            I have no problem accepting that motion is real. I do not think we can say with certainty that we know all motion is caused. Newton's laws do not say this, and verified quantum theory seems to refute this, with particles appearing out of nothing in motion. So scientifically speaking it appears to be much more complicated that motion and cause.

            But I can accept as a general implication of my own observation that if something is moving, something moved it. However, absolutely everything I have observed or can conceive of causing motion is material. The inference I get from this is that all motion appears to be caused by something material. You and Aristotle and Aquinas seem to be saying that despite the fact that everything we observe moving appears to be caused by something material, something immaterial was the cause.

            I think this is understandable for philosophers living hundreds of years ago when the (apparent) motion of the sun, magnets, wind and so on, seemed to have no material cause. It is less interesting now, unless there is a need to justify some kind of god concept.

      • Ben Posin

        "As I understand Your post, You're making the common mistake of reading the universal principle as a variant of "everything that exists has a cause", which is really absurd if a being without a cause is supposed to exist, as You rightly point out. Aquinas, however, doesn't make such an assumption, his principle would instead analogically read as "everything that begins to exist has a cause", which doesn't result in a logical inconsistency when admitting an uncaused being."

        This is another example of what I was talking about in my earlier reply to Brian: there's no content here, just a pretty blatant attempt to define something into existence. The only reason you/Aquinas posit the need for any sort of "uncaused being" is because you/Aquinas see everything that isn't God in the world as part of a chain of causes, necessarily part of a chain of causes. As I said in the other comment, I get that you want there to be something at the end different from everything else, but I don't you think you have any real explanation for how such a thing can be or what it would be like.

        • Andrej Tokarčík

          Hello, Ben. I read Your other post before, though I still don't know how to react. I think Aquinas's arguments are quite clear with respect to their logical structure. Talking about the Five Ways, the arguments have their premises and logical steps specified, leading to the conclusion. I'll try to reply to the only statements contesting Aquinas's arguments (the First Way in particular) that I see in Your posts (apologies if I missed anything) below:

          The only reason you/Aquinas posit the need for any sort of "uncaused being" is because you/Aquinas see everything that isn't God in the world as part of a chain of causes, necessarily part of a chain of causes.

          First, there is no need to make God an exception in this case. He as the first cause certainly still is (and has always been) a member of a causal chain, yet in a very special way. The first cause of a per se causal chain (which is in question here) is the only member of such a causal chain that has its own underived causal power. It is not in any way to imply, though, that the first cause is not part of such a causal chain.

          Second, whether it's true or not that everything in the world takes part in a causal chain, it does not constitute a premise of any of Aquinas's argument (as far as I am aware of). The closest principle of Aquinas's I can think of in this context is the principle of causality, discussed in my comment above, which can be taken to imply that "everything that begins to exist has a cause". But for what I know, Aquinas didn't think that this principle entails that everything in the world has a cause, or even that everything we can observe has a cause, since for instance he considered celestial bodies to be eternal (or he would grant that fact as part of a philosophical argument, if nothing else).

          As such, I don't see how Aquinas's arguments presuppose that everything is part of a causal chain. Certainly, it shouldn't be omitted that (in my view, at least) Aquinas's metaphysical project was to explain everything non-trivial, but I don't think that he assumed straight away that everything except God is non-trivial, and thus in need of explanation, and thus necessarily caused (in at least one of the Aristotelian four senses of causation) by another.

          Neither Trent or Aquinas has ever encountered anything in reality that has "no potential" (as he puts it}, and doesn't know what such a thing would be like or how it could exist.

          I'm not sure that this objection counts. It certainly isn't required that an explanation includes a full account of the conclusion of the explanation, for a full account of anything non-trivial would involve other things/phenomena, which would in turn themselves be in need of an explanation, and so on, but in that case all attempts to explain anything would necessarily extend ad infinitum (in which case no human knowledge is possible) or until arrived at a being which by its own simplicity is its own sufficient explanation (and which, for Aquinas, happens to be God).

          To look for a more practical counter-example, I think that the notions of dark matter and dark energy in contemporary physics also show how something can be used as an explanation of other phenomena, while remaining without full explanation. (I am no physicist by any means, though.)

          All the best,
          Andrej

  • Michael Murray

    After you knock over the first domino you start a chain reaction of dominoes hitting other dominoes. In fact, you could destroy the first domino after you’ve pushed it since it is no longer needed to keep the whole set of dominoes falling. Aquinas believed that sequential causes in the past, like a set of dominoes, could have occurred for all eternity.

    Interesting. I raised the domino example last year and was told it was not possible on logical grounds. I never got any such grounds and now I see why.

    • Tim Dacey

      "I do wish we could bring Aquinas forward in time from 1250 and teach him some real physics."

      I don't follow. What exactly qualifies as "real physics?" If I follow your reasoning, then it seems Newton wasn't doing "real physics" either

      • Michael Murray

        Well he didn't know anything about relativity or quantum mechanics and he was deeply confused about alchemy and astrology. If you like replace "real" by "modern" or "more real". We know more now than in Aquinas time, vastly more and more accurately.

    • DAVID

      There are some causal series which do not take place over time. For example, I can cause a stone on the ground to move by pushing it with a stick. Technically, the stick is causing the stone to move, but the stick would not be moving if it wasn't in my hand. All of this happens simultaneously: the stone is moved by the stick, and the stick is moved by my hand. This is the type of causal series that Aquinas is describing.

      • David Nickol

        All of this happens simultaneously: the stone is moved by the stick, and the stick is moved by my hand.

        Actually, it is not happening simultaneously. The force you apply to the stick at one end cannot reach the rock at the exact instant you apply it. The fastest it could possibly go from your hand to the rock (via the stick) is at the speed of light. To a human being, it will seem simultaneous at the distance of a few feet, but it is not. The same is true of hitting a golf ball.

        It is even more complicated than that, really, since relativity undermines the concept of simultaneity.

        • DAVID

          Even with a nanosecond of lag time, the fact still remains that the stone will only move while the stick engages it, and the stick will only move while my hand engages it. If my hand ceases, the whole series stops. Its very different from the "domino effect" in which the first cause in the series is rendered obsolete once it has produced its effect.

          • Peter Piper

            The OP relies on an in-principle distinct kind of causation, namely simultaneous causation. If it turns out to just be very fast (with, as you suggest, nanosecond-scale time lags) then the argument given in the OP doesn't work, and the second objection stands. Our best observations suggest that causation is only ever very fast (but bounded by the speed of light), rather than being simultaneous.

          • DAVID

            The argument does work because the difference between a "causal chain per se" and a "causal chain per accidens" is very obvious. In a "causal chain per se," the first cause must remain active in order for the causal chain to exist. Once the first cause ceases to act, the causal chain ceases to exist. This is different from a "causal chain per accidens" in which the first cause need not continue to act once it has produced an effect. In fact, the first cause is rendered obsolete once it has produced its effect (as in the first falling domino in a line of dominos). As you can see, its not absolutely necessary to suppose that a "causal chain per se" is a simultaneous action, although I think it is very helpful to think of it in that way.

          • Peter Piper

            As you are currently phrasing this, it begs the question, since your way of putting it supposes that any causal chain includes a first cause. So I think you mean something like `once an earlier cause ceases to act, the later parts of the causal chain cease to exist'.

            But even after this rephrasing you have a problem, for in fact there is a (nanosecond scale) delay between the earlier cause ceasing to act and the later parts of the causal chain ceasing to be present in all the examples.

            Thus there is a delay between the golfer ceasing to apply force to the club and the club ceasing to apply force to the ball (the delay here is longer because of the momentum of the club, but even if we ignore that there is still the delay due to the fact that information cannot propagate faster than the speed of light). For a short time, the later part of the causal chain (club applying force to ball) exists even though the earlier cause (the golfer) has ceased to act.

            As I said above, our best observations suggest that it is always like this. Such a delay is unavoidable.

          • DAVID

            Its hard for me to tell whether or not you are addressing what I wrote. I said that simultaneity is not necessary for understanding this particular type of causality. So I'm not sure why you belabor the point about there being a nanosecond of lag time.

          • Peter Piper

            I'm dealing with this sentence, from your definition of causal chains per se:

            Once the first cause ceases to act, the causal chain ceases to exist.

            What I'm pointing out is that it is false in the examples, because of the time lag. I'm guessing you didn't mean to imply that the chain should immediately cease to exist.

            Given this misunderstanding, I'd rather not carry on until I have a better idea of what you were trying to say. So would you mind rephrasing the sentence quoted above so that it is clearer what you mean? Perhaps you could also give your own favourite example of a causal chain per se, with an explanation of why that chain can't count as being per accidens?

          • DAVID

            Sorry for the delay. I guess that I would rephrase the sentence by saying that the continuing action of the first cause keeps the causal chain in existence. Even given the lag of one or a few nanoseconds, the entire causal chain nevertheless depends on the sustained effort of the first cause to keep all intermediate causes in motion. The stock example of this is a person moving a stone on level ground with a stick. The stone moves because of the movement of the stick, and the stick moves because of the movement of the hand which holds it. The entire causal chain (which, in this case, is very short with only one intermediate cause) ceases to exist when the hand cease to act. The hand could continue to move the stick, and consequently the stone, for hours, days, or even weeks. But once the hand stops, the stick and stone will most certainly stop (even taking into account possible lag time). What I have just described is a causal chain "per se." This is different from a causal chain "per accidens" which can be illustrated by a chain reaction of falling dominos. In the case of the falling dominos, the first cause can be designated as the finger that tips the first domino in the series. Once the finger has acted, the first cause is out of commission and the causal chain no longer depends on it for its continued existence. Each falling domino depends solely on the falling domino which precedes it. As long as each domino falls on top of the next one, the chain will continue. The line of dominos could stretch out for minutes, hours, days, or years--one domino falling upon the one in front of it--but, no matter how long it lasts, it will no longer be sustained by the first cause.

          • Peter Piper

            As far as the physics involved is concerned, there is no qualitative difference between the sort of causation occurring when a person pushes a stone with a stick, and that occurring when they set a chain of dominoes in motion.

            Let me illustrate this by talking in more detail about the second case: when a person pushes a stone with a stick, they are only directly imparting a force on the first few molecules, close to their hand. These molecules move along a bit, and push on the molecules further along the stick. These molecules in turn move along, and push on the further molecules. This carries on all along the stick, just like a chain of dominoes each pushing over the next. Finally, the atoms at the very end of the stick push on the stone. This is, of course, an oversimplified picture of what is going on, but it gives the right qualitative idea.

            A helpful point to notice is that the later parts of the causal chain are independent of the earlier parts, in the following sense: if the molecules half way along the stick were to move along for some other reason than being pushed by the molecules behind them, they would still press on the molecules in front, which would press on the ones in front of them and so on all the way to the stone, just as before. This is analogous to the fact that if a domino halfway along a chain falls over then the succeeding dominos will also fall, each in turn, even if what caused that halfway domino to fall was not the fall of the preceding domino.

            In particular, in order for the causal chain to continue from the halfway point to the end of the stick it is not necessary for the person's hand to still be pressing on the start of the stick. Although the timescales involved are much faster, it looks like this is not after all an example of per se causation, even in your sense.

          • DAVID

            As far as the physics involved is concerned, there is no qualitative difference between the sort of causation occurring when a person pushes a stone with a stick, and that occurring when they set a chain of dominoes in motion.

            In order to understand the difference between the two forms of causation, you would have to make macro-level distinctions. Physics cannot distinguish between a hand, a stick, and a stone. In terms of physics, these are all just particles in motion. But to say that physics does not have the conceptual framework to understand a hand, a stick, or a stone, doesn't mean that they don't exist. Likewise, it doesn't mean that "per se" causality doesn't exist; it just means that physics does not provide the means of describing it.

          • Peter Piper

            Even if I accept your claim that macro-level phenomena can remain inexplicable without invoking God although all the micro-level phenomena comprising them are explicable without such invocation, it is clear that we cannot maintain an in-principle distinction between per se and per accidens causation on your account (because there is no in-principle distinction between the micro- and macro- levels: it is just a matter of scale).

            Since the argument in the OP relies on such an in-principle distinct kind of causation, that argument fails even if we try to patch it up by using your definition of per se causation.

          • DAVID

            Two points:

            First, it sounds to me like you would be willing to argue that hands, sticks and stones don't exist. Is this correct? After all, if the micro/macro distinction is just a matter of scale, and our current knowledge of the micro level cannot account for various macro-level phenomena, then, according to our current understanding, these phenomena must not exist. In my opinion, it would be wiser to accept the discrepancies of our experience rather than discount the macro in order to make it gel with what we currently know about the micro.

            Second, I have to backtrack and leave open the possibility that there might be a way to explain "per se" causality in terms of physics. Just because I am ignorant of it, doesn't mean that it doesn't exist.

          • Peter Piper

            No, I think that sticks, stones and hands exist. I also think our knowledge of the micro level can (in principle) account for macro-level phenomena.

            In your second paragraph, you appear to be conceding that Aquinas' first way fails. Thanks.

          • DAVID

            Let me see if I understand you. You are saying that hands, sticks, and stones do exist. You are also saying that a hand which moves a stone with a stick is not in control of the movement of both the stick and stone. You argue that physics makes it impossible to accept that hands can have control over the movement of stones through the use of instruments such as sticks. If I've summarized your position adequately, then I won't argue any further. I'm just going to observe that your argument flies in the face of common sense.

            In my second paragraph, I'm simply admitting ignorance. That's not the same as a concession.

          • Peter Piper

            No, I am not saying that a hand which moves a stone with a stick is not in control of the movement of both the stick and the stone. You have not summarised my position adequately.

            You say you are just admitting ignorance. But at the very least, you are saying that you do not know that Aquinas' argument works.

          • DAVID

            No, I am not saying that a hand which moves a stone with a stick is not in control of the movement of both the stick and the stone. You have not summarised my position adequately.

            If this is not what you're saying, then it seems to me that you are in basic agreement with Aquinas. You may have a different way of describing the mechanism of "per se" causality, but you still believe that it exists. All that Aquinas would have you understand is that the hand is in control of the movement of both the stick and the stone. That's all. We shouldn't make it any more complicated than that.

          • Peter Piper

            It seems you are suggesting yet another attempt at a suitable definition of per se causation, namely that the initial cause is in control of the remainder of the causal chain. However, this is evidently not an in-principle distinction (since I can easily be more or less in control, depending on factors such as the flexibility of the stick).

            Furthermore, introducing the notion of control suggests that there should be some conscious being at the beginning of the causal chain (that is, it is not quite accurate to say that it is my hand which controls the stone: it would be more accurate to say that I control the stone by means of my hand and the stick). So per se causal chains will be rare, and in all cases where we can be sure that we have such a chain we will have already identified the first point in the chain and determined that it is conscious. But then either that first point will be God, in which case we have no need for the argument in the first place since we have a more direct way to find that He is there (note: this option never happens, as far as I can tell) or else we can identify the first point as a non-God being (like a guy with a stick) in which case we are no closer to proving the existence of God.

          • DAVID

            I need to back up again. Sorry. Are we both agreeing that control of movement includes the ability to give movement or to arrest movement?

          • Peter Piper

            That isn't quite true, because for example someone gliding in a hang glider is in control of the movement of the hang glider but is not able to arrest its movement. But I guess this is a side issue, so hopefully after rephrasing what you wanted to say you will be able to carry on with your argument.

          • DAVID

            Thanks. Just trying to make sure that I stick to what I know of Aquinas without adding foreign ideas. The full conceptual framework, as I understand it, must include the idea of actuality/potentiality. It must also includes change as a type of movement. All finite beings are a mixture of act and potential. This simply means that a finite being is actually someplace, or in some definite state, but it has the potential to be in some other place, or to change from one state to another. A thing cannot move or change by itself. In other words, it cannot move from a potential state to an actual state by itself. This is fairly straightforward in most cases. A hand cannot flex by itself but requires a network of muscles and nerves connecting it to a brain. The various systems of the body cannot operate without cells, cells depend on atoms, and this dependence moves further and further down into the quantum level. Nothing finite can move from potential to act strictly by itself.

            Aquinas is following Aristotle in his way of thinking on this. And Aristotle reasoned that there must be a being which is 100% act with no potential at all. Such a being with no potential requires no help for movement; such a being is the realization of all possible movement because it possesses all act within itself. It would be even better to say that it is act.

            Because this being is pure act, all finite beings beneath it receive the ability to move from potential to act because of it. Each level, from the quantum on up to the galactic, serves as an instrument (like the stick in the hand) to impart movement to the level above it. But all of these levels are simply instruments, or tools, in the hand of the purely actual being.

          • Peter Piper

            We seem to have left behind the distinction between per se and per accidens causation. Is the plan to return to it at some later point?

            Since you did not flesh out the argument, I in turn cannot work out whether the second objection discussed in the OP applies to your version of it. I do already disagree with one claim you make here (namely that a thing cannot move or change by itself), but if you want to discuss that it might be best to do it elsewhere in the comments, where I am already discussing it with Andrej Tokarčík.

          • DAVID

            Alright, I'll stick to answering what you wrote in a previous post without introducing anything else for the time being. You wrote:

            However, this is evidently not an in-principle distinction (since I can easily be more or less in control, depending on factors such as the flexibility of the stick).

            A flexible stick would make it hard to demonstrate the principle. But you can't disprove a principle with a bad demonstration.

            Furthermore, introducing the notion of control suggests that there should be some conscious being at the beginning of the causal chain

            Perhaps not. We all have Internet Service Providers. Our connectivity to the internet is, for the sake of this example, located in the servers that are operated by the ISP. These servers are maintained and updated, but for the most part, they do not require conscious intervention in order to operate. Now the entire infrastructure that runs between our computers and the servers is an instrumental cause. In other words, the infrastructure cannot, of itself, provide us with connectivity. Our connectivity is controlled by the servers and the infrastructure acts as a stick between the hand and the stone. If we allow that the servers are the first cause, and that our computers are the final causes, we might allow that per se causality does not necessarily need a conscious agent.

          • Peter Piper

            The point of the example of the flexible stick is that it shows that we cannot divide situations at all cleanly into those where an agent has control and those where the agent does not have control. The boundary is too fuzzy and unclear. But the argument relies on such a clean distinction, if per se causation is defined in terms of control.

            Regarding your second point: I will concede that it is common to extend the word `control' to cases like this. Since such cases are still rare, and the first cause in such cases is still both clearly identifiable and complex, my rebuttal works just as well even if we do this.

          • DAVID

            The point of the example of the flexible stick is that it shows that we cannot divide situations at all cleanly into those where an agent has control and those where the agent does not have control. The boundary is too fuzzy and unclear.

            In order to prove this type of causation, it is only necessary to assume that control is possible. It is not necessary to suppose that an agent has complete control in all possible circumstances. I should add that control, in the sense that I'm using it, is primarily to indicate the ability of something to "give movement" to another thing. I'm not so much concerned as to whether something has control as a driver has at the wheel of a car.

          • Peter Piper

            In that case, I don't know what you mean by `control'. Could you rephrase it in other words? I also don't understand the formulation `give movement', except in a metaphorical sense.

            Regarding your first point: if there is no clear distinction between per se and per accidens causation then there is no logical reason why a rebuttal to an argument using per accidens causation would not also apply to an argument using per se causation.

          • DAVID

            In that case, I don't know what you mean by `control'. Could you rephrase it in other words?

            Control is basically the power to move or to change something. Change is a form of movement and so the definition of control can be simplified to the power to cause movement in something else. My reason for defining control in this way is simple: I don't see how a person can have control over something else unless that person has the power to move or change it in some way.

            if there is no clear distinction between per se and per accidens causation then there is no logical reason why a rebuttal to an argument using per accidens causation would not also apply to an argument using per se causation.

            The key distinction between the two forms of causation is, as I understand it, the difference between a principle cause and an instrumental cause. Per accidens causation involves principle causes only. Per se causation involves one principle cause but is followed by an instrumental cause, or a group of instrumental causes. Perhaps you can see how this distinction is illustrated in the two examples which I have given above. The falling dominos illustrate a series of principle causes (per accidens causation) and the hand/stick/stone example illustrates a series with one principle cause followed by an instrumental cause (per se causation).

          • Peter Piper

            My reason for defining control in this way is simple: I don't see how a person can have control over something else unless that person has the power to move or change it in some way.

            By making your definition broad like this, you avoid excluding any actual cases of control from fitting your definition. But you seem to have gone too far in the opposite direction, and made the definition so broad that it includes cases you wanted to exclude. For example, imagine a woman sitting at one end of a chain of dominoes. Does she have the power to move or change the 100th domino? Yes: she could push over the first domino and so start the whole chain of dominoes falling over, until eventually the 100th fell. She would then have successfully moved the 100th domino. Thus, on your definition, she controls the 100th domino.

            In your final paragraph, you introduce yet another new distinction, namely that between principal and instrumental causes. Since I am not sure what you mean by this distinction, I'd appreciate a clarification.

          • DAVID

            In your final paragraph, you introduce yet another new distinction, namely that between principal and instrumental causes. Since I am not sure what you mean by this distinction, I'd appreciate a clarification.

            An instrumental cause has no causal power in itself. A principle cause, relatively speaking, does have causal power in itself.

            In the hand/stick/stone example, the stick is an instrumental cause. By itself, it cannot move anything. It must be moved by the hand (a principle cause) to have any causal power. It might help to think of an instrumental cause as an "instrument" or tool. The stick is the tool by which the hand moves the stone.

            A principle cause, relatively speaking, has power in itself to cause an effect. In the other example which I've used, each falling domino is the principle cause of the falling domino in front of it. Let me give an even better example. A father and mother are the principle causes of their son or daughter. Should the son or daughter grow up and have children of their own, then the son or daughter will be the principle causes of their own children. Quite obviously, between the grandparents and the grandchildren, there is no instrumental causation at work. The parents of the grandchildren are not instruments or tools by which the grandparents produce grandchildren. The parents possess the power to produce grandchildren on their own; they do not require any intervention from the grandparents. The grandparents might not even be alive at that point.

          • Peter Piper

            It looks like on this account dominoes are instrumental causes. For a domino cannot move itself, and must instead be moved (for example by the previous domino).

          • DAVID

            The difference between the two forms of causation is not whether any particular thing can move itself, but whether any particular thing has causal power in itself. Aquinas did not think that anything short of God possesses complete autonomy of movement. Given that fact, the question is therefore not whether anything is moving itself, but whether the causal chain possesses the characteristics of per se or per accidens causality.

            A helpful way to distinguish the two forms of causality is to consider the difference between a hierarchy and a series. Per se causality is hierarchical: each level of causation is sustained by a level directly above it (the stick's causal power being sustained by the causal power of the hand). Per accidens causality is serial: one domino has an effect on the next domino, which has an effect on the next domino, which has an effect…etc.

          • Peter Piper

            I don't understand the formulation `has causal power in itself'. We still haven't settled on a workable distinction between per se and per accidens causation either.

            I think the main term I would need to understood before I could follow your second paragraph is `causal power'.

            I'm sorry that we seem to be getting bogged down in getting terms clear, but the fact is that I genuinely don't yet see any clean qualitative separation of causation into two kinds and I really would like to understand the one you are trying to clarify.

            I have a picture in my head, and I want to clarify whether it is relevant. The picture is like this: a woman is holding a stick, and using it to push a stone. But then she lets go of the stick. Now the stick falls to the ground (because of gravity). Because it is no longer in contact with the stone, it can't push the stone any more. Is this what you mean by saying it has lost its causal power?

            To clarify this, imagine a slightly different set-up. In this set-up, the stick is hanging from the ceiling by a couple of strings, one at each end. So now when the woman lets go of the stick, it doesn't fall to the ground, but remains where it is, in contact with the stone. If it were to move along for some other reason than being pushed by the woman, it would cause the stone to move. So is it still per se causation for the woman to push the stone with such a stick?

            The last two paragraphs are probably not relevant, but this is one thought I had about what you might possibly mean and I wanted to clear it up.

          • DAVID

            I don't understand the formulation `has causal power in itself'.

            Something with "causal power in itself", is that which has the power to cause an effect in something else. In terms of this discussion, it is the power to cause movement in something else. This does not necessarily mean that something with "causal power in itself" has the power to move itself, it simply means that it has the power to cause movement in something else.

            The picture is like this: a woman is holding a stick, and using it to push a stone. But then she lets go of the stick. Now the stick falls to the ground (because of gravity). Because it is no longer in contact with the stone, it can't push the stone any more. Is this what you mean by saying it has lost its causal power?

            The stick has lost its causal power primarily because it is no longer being held by the hand. The stick is an instrument which the hand uses to move the stone. The stick is an "instrumental cause." Instrumental causation is a necessary part of per se causality. You could expand the example: imagine a hand moving a stick, which moves a stone, which moves a second stone next to it, which moves a tin can. In this example, you do not have one instrumental cause but 3: a stick and two stones. The stick and two stones will continue to move only insofar as the hand continues to move. Once the hand ceases to move, the causal series terminates (even allowing for a nanosecond time lag).

            The main difference between per se and per accidens causality is that the latter does not involve instrumental causation.

          • Peter Piper

            Do you agree that the woman could cease to touch the end of the stick (thus removing her ability to cause it to move) a short time before the stick ceases to cause the stone to move?

            If so, what do you think is going on in this short time? Do you think this causal chain very briefly switches from being per se to being per accidens?

          • DAVID

            In this particular example, it sounds like the stone is not being pushed by the stick but is balancing on top of the stick. Have I got that right?

          • Peter Piper

            No. If you mean the example without the strings, then there is nothing unusual going on. If you mean the example with the strings, the stick is still horizontal, supported by strings attached at each end. The woman stands at one end and pushes, and the stone is in contact with the other end, so that the woman is pushing the stone with the stick.

            So: do you accept, in either case, that the woman could cease to touch the end of the stick a short time before the stick ceases to cause the stone to move?

          • DAVID

            Its possible that, depending on how the stick moved once it were dropped, or once it was released in whatever way, it might budge the stone forward, or even backward, for an instant. But it doesn't seem to have much bearing on the analogy. The analogy is a simple illustration of a general concept. Its not supposed to be a model of mathematical precision.

          • Peter Piper

            Since you have accepted that the stick still pushes on the stone for a short time after the woman lets go, do you now accept that the stick retains its causal power for a short time after the woman lets go?

          • DAVID

            I can accept that. I would suppose that what you said earlier is true: there's a transition from per se to per accidens causality. Once the stick is no longer in the hand, it is no longer an instrumental cause. Its causal power, at that point, is "accidental."

          • Peter Piper

            On your current account, the stick briefly gains `causal power in itself', which it did not have before, when the woman lets go of it. This makes me even more confused about what `causal power in itself' means.

          • DAVID

            Why are you confused?

          • Peter Piper

            I don't see how letting go of something can grant it the power to cause motion in other things.

          • DAVID

            Its no different from tipping over a domino. Once you've tipped over the domino, that domino is in motion and has the power to move another domino in proximity to it.

          • Peter Piper

            But letting go of the stick doesn't set the stick in motion: the stick was already in motion. So why shouldn't we say that the stick had the power to move the stone before?

          • DAVID

            We're not saying that the stick didn't have the power to move the stone before. We're saying that the stick goes through a transition. It transitions from being an instrumental cause in a per se causal chain, to being a principle cause in a per accidens causal chain. In other words, the stick transitions from deriving its power to cause motion from the hand to having its power to cause motion purely from the fact that it is in motion.

          • Peter Piper

            You said earlier

            Something with "causal power in itself", is that which has the power to cause an effect in something else.

            So you seem to be saying that the stick has causal power in itself even whilst the woman is still holding it. That is, you seem to be saying that the causal chain was only ever per accidens, whilst insisting it is also per se. I hope this illustrates why I am getting confused.

          • DAVID

            My apologies if I've made it confusing. I'm making a distinction between something having causal power in itself and something having causal power by virtue of something else.

          • Peter Piper

            You have not yet made any such distinction clear. The sentence I quoted above was your definition of `causal power in itself'. If you want to introduce yet another distinction by giving a different definition of this phrase then go ahead.

          • DAVID

            Sorry, I edited my last response after writing it. I was hoping you'd see the edit so you'd see the new definition. Here's what I wrote:

            My apologies for making it confusing. I should have defined "causal power in itself" as something which is in motion, the motion of which is not sustained by something else.

          • Peter Piper

            Everything on Earth is in motion, because of the rotation of the Earth. Depending on whether you count such motion as being sustained by the Earth or not, either everything on Earth has causal power in itself (in your new sense) or nothing on Earth does.

          • DAVID

            I'm not sure that I follow you. Are you saying that if a woman moves a stone with a stick, the stick has causal power in itself?

          • Peter Piper

            Before I can answer that, I need you to settle on a definition of the phrase `causal power in itself'. I'll then try to work out whether that definition applies to the case of a woman moving a stone with a stick.

          • DAVID

            Something with the power to cause an effect in something, the power of which is not sustained by a first cause.

          • Peter Piper

            Suppose that B would continue to have the power to cause an effect in C even after A ceased to act on B. Would you say that the power of B is sustained by A?

          • DAVID

            Did you see my second response to your post?

            Although, technically speaking, if B were to continue to have a sustained effect on C even after A had stopped, then B would become the first cause in this particular chain.

          • Peter Piper

            You haven't answered my question (or at least I am unable to determine an answer from what you have written). Please do so.

          • DAVID

            Suppose that B would continue to have the power to cause an effect in C even after A ceased to act on B. Would you say that the power of B is sustained by A?

            Please provide an illustration of what you're talking about.

          • Peter Piper

            I really want the answer in general, but here is an illustration: domino A pushes on domino B. Domino B, still being pushed by domino A, falls and hits domino C. If domino A were to stop pushing domino B, domino B would nevertheless continue to push on domino C. So, is the causal power of domino B currently being sustained by domino A?

            This is just an example, and I would like to know your answer in the general case.

          • DAVID

            Given the example, I would not say that the power to cause an effect is being sustained by another cause. It would be enough for A to fall on B regardless of whether A continued to touch B as it fell on C.

          • Peter Piper

            Then, given our discussion above, it seems that from your definitions the stick does have causal power in itself. For it would continue to push the stone even if the woman were to cease to act on it.

          • DAVID

            It would have causal power in itself, from the moment it left the woman's hand to the instant it ceased moving. But while the stick remained in the woman's hand, it would not have causal power in itself.

          • Peter Piper

            This was the reason for my question: let A be the woman, B the stick and C the stone. Then B would still push on C even if A were to stop acting on B. So we do not say that A is sustaining the causal power of B, even whilst A continues to act on B. If you wish to introduce yet further distinctions to avoid this issue, then feel free to do so. You can take your time, since I can't carry on with our conversation today.

          • DAVID

            The distinction that I would make is between something acting on something else and something "sustaining the causal power" of something else. Domino A works its effect at the point of contact with domino B. After the point of contact, it doesn't much matter what happens to domino A. It could continue to fall on top of domino B, but it could just as easily disappear. The point being: in your first illustration, you did not give an example of A "sustaining the causal power" of B.

          • Peter Piper

            Repeating the terms that still need to be adequately defined does not help. Nor does the idea that domino A could `just as easily disappear' and domino B would continue to affect domino C. For the same is true in the other example. The woman could `just as easily disappear', and the stick would continue to affect the stone (albeit for a much shorter time).

            I'd like to introduce a simple example, which I think defies the dichotomy between per se and per accidens causation. It is a card flourish called the ribbon spread and flip (or more precisely the flip part). You can see this flourish in this youtube video: in fact, it is performed within the first ten seconds of the video.

            It is clear that the flip involves some sort of causal chain moving from one end of the pack to the other, which sustains itself after the initial impetus from the performer - in this sense it is like a chain of dominoes (and in fact, the man presenting the video makes exactly this comparison at 3:32). On the other hand, each of the cards involved is being pushed by the cards behind it the whole time, and relies on being pushed like this in order to sustain enough force to move the next card.

            So I don't think this example fits the per se/per accidens dichotomy.

          • DAVID

            For the same is true in the other example. The woman could `just as easily disappear', and the stick would continue to affect the stone (albeit for a much shorter time).

            If the woman were to disappear, the fact that the stick would continue to affect the stone for a short time is irrelevant. The point is that, while the stick is being moved by the woman's hand, the hand is sustaining the stick's causal power. Unless you address this fact, we're at an impasse and it would be fruitless to continue.

          • Peter Piper

            You have not explained the phrase `sustaining the stick's causal power'. When I asked for clarification, you only gave it in a special case, despite my repeated requests for clarification in general. I tried to move the conversation on by applying your clarification in a very similar case, but you refused to accept this. Nevertheless, we cannot proceed until it is clear what it means for something to sustain the causal power of another thing.

          • DAVID

            I should be even more precise: something with the power to cause an effect in something, the power of which is not sustained by another cause.

          • DAVID

            This is second reply to your post because I want to anticipate a question which you might have. You might wonder how the domino example (which illustrates per accidens causality) does not involve "instrumental causality."

            If a woman uses her finger to knock down the first domino in a series of falling dominos, this causal series does not depend on the sustained movement of the woman's finger in order for the causal series to run its course. Once the woman's finger knocks down the first domino, her finger is no longer needed. This is different from the hand/stick/stone example in which the hand's continued movement is needed to move both the stick and stone.

          • Irenist

            Great point, Peter Piper!

            The hand-stick-rock-leaf example is meant to illustrate per se causal series by contrast with Abraham-Isaac-Jacob per accidens series. The key point isn't the simultaneity (which is just an artifact of Aquinas' example) but the instrumental/dependent as opposed to independent relationship the members of the series have to each other. The Thomist theologican Suarez once illustrated per se series with a sculptor and his statue, which indicates that simultaneity isn't the issue.

            The per se series distinction is being deployed by Aquinas to illustrate the ontological dependency of anything for its existence upon God, and this ontological dependency is a logical relationship, not a relationship of efficient causality of the sort measured by scientific observations of the discrete granularity of micro-scale spacetime.

            This post might be helpful:
            http://edwardfeser.blogspot.com/2010/08/edwards-on-infinite-causal-series.html

          • Peter Piper

            Thanks for that. You might have noticed that I don't understand the conceptual foundations of this distinction very well. I'm afraid it will take me some time to read through Feser's post (as well as the article it is responding to), but I hope I will eventually be able to understand and reply sensibly to what you are saying here.

          • Irenist

            Well, a lot of us (like me!) are very, very, very far from understanding the physics that informs your critique of simultaneity in Aquinas' examples, so if you happen not to know some metaphysics, no worries! (Frankly, although my grasp of the metaphysics is deeper than of the modern physics by a long, long ways, it's still very far from where I'd like it to be. We're fellow students.)

        • Andrej Tokarčík

          Hello David. The problem appears to lie on the side of the exposition given in the article, namely it is not quite correct to say that per se causal chains are characterised by the simultaneity of operation of their members. Rather, per se causality is distinguished by the instrumental nature of the members of such a chain, with the only exception of the first member, which imparts causal power to the whole chain. That is, the per se causal chains can have no causal power whatsoever, if there was no first cause, upon which the other, instrumental causes do absolutely depend (regarding the exercise of their causal power as members of the chain, anyway).

          Whether it makes sense to assume that any such causal chains do actually exist in reality is a separate discussion. At this point I just wanted to note that the First Way cannot be simply discarded "since relativity undermines the concept of simultaneity".

          Cheers,
          Andrej

          • DAVID

            Thanks, Andrej. That's a good distinction and I will use it. To tell you the truth, though, I'm still unclear why it is supposed that simultaneity is not the proper way to think of it. It has been explained to me that a cause and effect requires a simultaneous meeting of the two. For example, a rock cannot break a glass without first coming into contact with it--a causal series per se requires a simultaneous meeting of cause and effect all the way down the causal chain. It seems to me to be hair-splitting to say that it does not involve simultaneity.

          • Andrej Tokarčík

            Hello, David. First of all, allow me to make a little correction to Your statement that "a cause and effect requires a simultaneous meeting of the two", which is only partially true. I think the proposition is true not for causes in general but for immediate causes only, i.e. the immediate cause of an effect is simultaneous with that effect. Nitpicking, perhaps, but one never knows if it doesn't get crucial at a later point... :)

            As for simultaneity, the main lesson is to remember that the definition of per se causality involves instrumentality rather than simultaneity. Furthermore, it does not render simultaneity completely irrelevant, it's just not as fundamental as instrumentality is. There might be per se causal chains involving non-simultaneous members, but the question of the First Way's being valid is not influenced by it.

            I think the following from Daniel Smith, a commenter at Feser's blog, is a good way to understand the difference for a layman (that is, me included):

            As for the difference between series per se and per accidens: it might help to think about it in terminus...

            Does the father dying cause the son to die? No. The son can keep on living regardless of what happens to the father. It is a series per accidens.

            Does the hand stopping cause the stone to stop? Yes. The stone will stop moving because the hand stopped moving (even if not instantaneously). It is a series per se.

            (To be honest, I draw most of the content of this post from reading of the discussion section thereat.)

          • DAVID

            Thank you. Good points.

          • David Nickol

            Andrej, thanks for your clarifying remarks. It looks like notions of sequential and simultaneous do not actually figure in the discussion at all. Also, if I may be so bold as to criticize Aquinas, it seems to me his concepts of motion are out of date. (He did not know Newton's First Law—not surprisingly.) When a stick is pushing on a rock, or an engine is pulling a train with many cars and a caboose, first, the actions do not happen simultaneously. The caboose, for example, does not move the instant that the engine moves, but at best begins to move when the engine moves plus the time it takes for light to travel from the engine to the caboose. And in the case of the caboose, it doesn't stop moving because the train stops pulling it. If all of the train except the caboose were somehow to vanish into thin air, the caboose would continue to move, and what would stop it would be forces like friction and air resistance. If the first domino in the sequence were to vanish into thin air after it had fallen and pushed the second domino, the chain would continue.

            At this point I just wanted to note that the First Way cannot be simply discarded "since relativity undermines the concept of simultaneity".

            Apparently simultaneity is no longer relevant to the argument, correct? It seems that neither per se causality nor per accidens causality relies on the concept of simultaneity. Am I correct in saying that Aquinas had no problem with infinite regress in what we are calling per accidens causality? He seemed not to have a problem with the world (universe) having existed from all eternity.

          • Andrej Tokarčík

            Hello, David. See my reply to DAVID, it cannot be said that the simultaneous is to be totally ignored within the discussion, because most of the per se chains we encounter are simultaneous (although the metaphysical concept itself does not depend on this property). Consider the categories of Your counter-examples: You're talking about either starting a movement or stopping it. But the simultaneity pointing towards a first cause is of that kind which happens in the course of a movement.

            To quote an anonymous David from the discussion already linked to:

            As TheOFloinn pointed out, the hand, stick, and stone do move simultaneously - 'a hand pushing a stone' is different from 'a hand beginning to push a stone that had been at rest' -, so your objection on that point doesn't really get off the ground at all, does it?

            [...]

            It seems, and I wonder if it's worth noting, that Aquinas believed that there is a time (tempus medium) between any two instants. Thus if you are referring to the end of rest and the beginning of motion (say, of a stone) Aquinas would not even have said that these are simultaneous. Cf. ST III.75.7 ad 1: "there must of necessity be a mid-time between every two signate instants [e.g., end of rest and beginning of motion] in connection with that change." This follows, it seems, from the fact that the two instants designate a before and an after and time just is the measurement of change in terms of before and after. Likewise there will
            be a time between the instant before the stick contacts the stone and the instant after it has contacted the stone.

            Now, to Your next question:

            Am I correct in saying that Aquinas had no problem with infinite regress in what we are calling per accidens causality? He seemed not to have a problem with the world (universe) having existed from all eternity.

            He had a problem, not philosophically though, but on faith. Aquinas would happily grant that the universe is eternal or that a per accidens series can regress infinitely into the past for the sake of argument, for he didn't believe that the question of whether such an infinite series is possible to exist can be resolved by a philosophical/scientific argument. But he certainly didn't himself believe that such an infinite chain can exist, since he was a Christian and accepted on faith the account of creation given in Genesis, which describes God creating the universe in time. At least, that's my understanding.

            Cheers,
            Andrej

    • Irenist

      I do wish we could bring Aquinas forward in time from 1250 and teach him some real physics. He was very smart and I'm sure he'd really enjoy it.

      So true! I once read somewhere that, without even getting into controversial frontiers of physics stuff, all anyone has to do is pick up any decent high school level calculus, chemistry, physics, or biology book to be immersed in discoveries that almost any of the ancients would've given their eye teeth to know. Made me feel really grateful to live now, and it's a reflection I return to often.

  • Lamont

    Although the argument from motion is
    interesting, it does prove the existence of God because it does not
    take into account the existence of self-moved movers. A self-moved
    mover is anything that moves by its very nature and does not require
    anything else to put it into motion. The most common example of this
    is energy. It is the nature of energy to be in motion, and the
    vibrations which constitute the essential or substantial form of
    energy are always in motion. Since matter is put into motion by
    energy, any motion that we can observe can be fully explained by the
    energy which produced that motion. If you ask where the energy came
    from, the answer is that, as far as we know, energy can neither be
    created or destroyed. It can only be changed from one form into
    another or converted into matter. Of course it may well be that God
    created the very energy out of which our universe is made. If that is
    true, it would require some additional argument to establish it as a
    matter of natural knowledge.

  • Stew

    Trent,
    Aquinas made the arguments; they were discredited by the objections you mention. Re-wording the arguments doesn't refute the objections - the arguments are the same, the objections are the same and they still refute the arguments. Try again.

  • Steven Dillon

    Thanks for posting this Brandon, Trent has done a good job of addressing these objections. His claim that God has no potential raises a few questions in my mind. For example, without 'any' potential, it seems that God has no free-will, because he has no potential to choose to do one thing rather than another.

    • Lionel Nunez

      I suspect you misunderstand of the term; don't ask me how, it just doesn't feel like potential was used here in the same way aquinas used it.

    • It also seems to undermine omnipotence, since God would have no potential to do anything which he did not actually do.

    • Danny Getchell

      It also raises the (previously asked) question of why there are any non-God objects, since God with no universe suffers no loss in actualized potential compared to God plus a universe.

    • Tim Dacey

      Hi Steven,

      I share your doubts on this issue. I think reading on the 'essence-energies distinction' popularized in the Eastern Orthodox Church may address your point, however it will become clear to you that the Roman Catholic Church has traditionally been critical of this view. I only mention it to you because (i) I am an Eastern Orthodox Christian, not a Roman Catholic Christian and (ii) I think you may find it interesting!

      Here is a wikipedia link: http://en.wikipedia.org/wiki/Essence–Energies_distinction#Roman_Catholic_perspectives_on_the_essence-energies_distinction_in_God

      If you want a more technical read though consider this book...

      http://www.amazon.com/Aristotle-East-West-Metaphysics-Christendom/dp/0521035562

      • Steven Dillon

        Brilliant, thanks for the book recommendation Tim!

  • Peter Piper

    Since nothing can move by itself …

    I can.

    • Andrej Tokarčík

      Are You the cause of Your ability to move Yourself? If so, how come You can lose it, ever? If not, has the quoted principle been rebutted?

      • Peter Piper

        The quoted principle is `nothing can move itself', and not `nothing is the cause of its own ability to move itself'. Thus my counterexample applies.

        • Andrej Tokarčík

          The principle is not limited to local motion. To move in the Aristotelian sense means to reduce potency to act. If You Yourself are not actualising Your (by itself merely potential) ability to move, there must be something else that is.

          • Peter Piper

            What is involved in `actualising my ability to move' beyond moving myself?

          • Andrej Tokarčík

            The fact that You're moving is just a consequence of Your actual ability to move, and not vice versa. Your ability to move remains in act even in situations when You're not moving Yourself. What is the cause of Your actual ability to move Yourself?

            Cheers,
            Andrej

          • Peter Piper

            Thanks for taking the time to explain that. It seems that once more you are working with a different principle than `nothing can move itself', a principle more like `nothing can actualise its own ability to move'. But my counterexample was to the principle `nothing can move itself', since that is the principle the OP relies on.

            Perhaps you would like to make a different argument from that in the OP. Feel free to do so.

          • Andrej Tokarčík

            Peter, sorry if I should have made myself more obvious, see my other comments under this article for more information if You are interested.

            The point, none the less, is that the OP does not rely on the principle "nothing can move itself" as though it was concerned with local motion exclusively. Aristotle and Aquinas (whom the OP attempts to defend, while obviously assuming some familiarity with their basic terminology) understand motion in a very broad sense, meaning any change whatsoever. As such, You can't explain Your movement by pointing to Your will (or what) and saying that's the end of it, that nothing else than You/Your will is required. For even if Your will caused a change in Your location, what explains the change of Your will? Is it its own cause? If not, the principle hasn't been rebutted.

            Best,
            Andrej

            P. S.: A more serious analysis of an instance of human locomotion would run thus: You move Yourself only insofar as the potential for motion in Your legs is actualised by the flexing of the leg muscles, and their potential for being flexed is actualised by the firing of the motor neurons, and the potential for the motor neurons to fire is actualised by other neurons, and so on. (Cf. Feser's Aquinas, pp. 11-12.) As You can see, "You" or Your will never get involved as movers/changers. (Perhaps unless You are a Cartesian dualist.)

          • Peter Piper

            You say Aristotle and Aquinas were working with a broader notion of what it is to move. Great! If something is an example of a less broad notion then it will also be an example of a broader notion. So my counterexample remains a counterexample. I haven't brought my will into the discussion, and don't see why I should. The question of just how I move myself is beside the point, if I do in fact do so.

            Your PS begins with a concession that I do move myself. The fact that it is possible to tell a more detailed story about this, involving information about which signals go along which nerves to which muscles and so on, does not make it false. So the counterexample remains.

          • Andrej Tokarčík

            You're right, my P.S. should have begun with ``You "move yourself"'' :)

            The broader notion of motion entails that "What is the cause of Your ability to move Yourself?" is a legitimate question, since we're looking for a sufficient reason of Your movement and "You" is not an answer that wouldn't demand a further explanation.

          • Peter Piper

            The broader notion of motion entails that "What is the cause of Your ability to move Yourself?" is a legitimate question

            How does it entail this?

  • Peter

    Although it would have appeared so in Aquinas' day, as indeed it does nowadays, there is not such a thing as simultaneous action. Citing the golfing analogy, the electrical impulse from our brain to our arm muscles, the swing of the club and the transfer of energy from the club to the golf ball, all require time which is mostly imperceptible to our senses. There is no distinction between sequential and simultaneous causes except for the duration of time between actions and our ability to perceive it..

  • "we must be careful when using or attempting to refute them because they are easily misunderstood"

    Fragility of an argument to perturbations in diction is a pretty good sign, all on its own, that the argument was never more than unsound wordplay.

    • Andrej Tokarčík

      Or perhaps it shows nothing but that the arguments are more than 700 years old, and people nowadays tend to think in different terms than back then :)

      • Like Trent Horn on this page, many defenders of Thomism, when faced with criticisms in ordinary language versions of the arguments, say that we really have to study up on and use the exact same terms Thomas used. Then when critics do that and still have basically the same objections, they are told they need to study up on the complete worldview of the Scholastics, and that if they do that then it will finally make sense. Then when the critics do that and still have basically the same objections, they are told they need to study yet another book, and another, and another...

        I've been down that road and I now reject it. If the arguments were ever sound, then they could survive being transposed out of jargon into ordinary language and modern methods of proof. If that can't be done, then the most charitable interpretation is that the old versions of the arguments must be developed into and superseded by arguments that satisfy modern demands for rigor.

        • Andrej Tokarčík

          I think the problem is not with the objections themselves*, rather, the problem seems to me to be that there are simply too many people going straight to Thomas's own summaries of the arguments and subsequently reading into them the modern understanding of the words used therein. In my previous comment I reacted the way I did because the vast majority of objections against Aquinas that I've encountered are based on objective misunderstandings (e.g., "motion" = the process of local motion) precisely because people for some reason feel like there is no significant gap between our current thinking and the thinking back then (or, perhaps, that our knowledge is a superset of theirs with the superstitious bits removed) that they don't hesitate to go directly to the original.

          I think there are many modern commentaries of Aquinas, but You're right that their authors usually (and perhaps too often) take the route of explaining the old Scholastic terms, perhaps even with the implicit goal of showing to those who have already gone through the arguments before and rejected them that their rejection was unfounded. One aspect that cannot be underemphasised, though, is that medieval philosophy does challenge the modern worldview (the topic of the overtly popular mechanical/quantifiable conception of matter comes to mind), and too aggressive an "update" of the original philosophy may result in a loss of the (in my opinion desirable) challenge to the modern understanding -- to that end, it is not unreasonable to suppose that the constant factor of "I cannot think as I usually do" when dealing with explicit medieval terminology may turn out to be essential. But still, even with the modern expositions available, too many tend to confront Aquinas directly rather than read modern commentaries such as Feser's.

          Anyway, You raise really good points with regards to the method of dealing with medieval philosophy, and the unrespectable tendency of sweeping objections under the carpet of infinite amounts of books. Thank You!

          _____
          * - However, I think that bringing a few additional terms into the discussion in order to reveal a logical inconsistency in the objection raised is a legitimate response. Of course, the logical inconsistency would usually be there only when Thomistic understanding of the notions was assumed. The point of such an endeavour would, none the less, remain inasmuch as it shows that the objection actually doesn't make Thomism logically inconsistent, but that the one raising the objection doesn't find Thomism to be an appealing philosophical framework. Which in the end pushes the whole discussion into the domain of "Which philosophy does correspond to the reality?" instead of the original "Your argument is invalid!"

  • The article doesn't explain much at all.

    He says that everything in motion only moves because it has a potential to move.

    OK, so he said that. Why should we believe it?

    Since nothing can move itself

    or that?

    an object can only move if its potential to move is activated by something outside of it

    or that?

    But what makes God different from anything else is that he has no potential to move or change.

    or that?

    God is pure motion itself (or what Aquinas calls act)

    or that?

    Nothing changes God in order to bring about effects in the world. Instead, God brings about effects by his own power.

    or that?

    If we're using the ordinary meanings, then there's no reason to grant all these assumptions without some evidence for them. And if on the contrary these are axioms rather than assumptions, because the author wants to define the words that way, then we have no reason to think the definitions correspond to reality without the same evidence.

    • Andrej Tokarčík

      Hello, Noah, I think that the article presupposes some knowledge of the terms used in the proof and motivation for their use, which is why they may seem to be unjustified. Very shortly, I'll try to explain how the ancients and medievals arrived at the notions they used to explain the world that are relevant for the First Way, and why these notions haven't been made outdated since then, in my opinion.

      He says that everything in motion only moves because it has a potential to move.

      OK, so he said that. Why should we believe it?

      For completeness, it may be useful to note that Aquinas, following Aristotle, didn't meant motion exclusively as local motion but much more generally as any change in quality or in quantity. Thus, for instance the principle "everything in motion only moves because it has a potential to move" that You quote should be understood as "everything undergoing a change only changes because it has a potential to change". Of course, this rephrasing (nota bene, without any change in the meaning whatsoever) still doesn't clarify why this principle should be viewed as a law of objective reality, which leads us to a little history lesson.

      The distinction between potentiality and actuality originating with Aristotle was basically developed as a reaction to avoid two unintuitive solutions of the problem of reconciling sense data (which indicate that beings change) with the principle of non-contradiction (stating that it is impossible for the same thing to be and not to be at the same time and in the same respect). Aristotle thus sought a middle way between Parmenides, who denied the reality of motion, rendering the senses not trustworthy for the end of determining the nature of the universe, and Heraclitus, who identified the reality of motion and being, effectively reducing the principle of non-contradiction to a mere rule of speech.

      Since Aristotle accepted neither of this views, it was necessary for him to postulate a real and objective medium between being (actuality) and non-being, along which changes in actual beings could be realised. And this medium is precisely what is meant by "potentiality", which automatically leads to the formulation of "everything is in motion because it has a potential to move". One cannot avoid an equivalent of the concept of potentiality, if Parmenides's static universe is to be avoided.

      On the other hand, with regards to Heraclitus, Aristotle replies that the principle of non-contradiction is a law of objective reality. I don't know about his actual reasons, but I'd personally say that if the principle of non-contradiction wasn't a law of reality, it would follow that the reality contains an absurdity, in which case there is no order in the universe and no knowledge of the natural world can be inferred.

      (Most of this information is derived from Chapter 5 of Reality: A Synthesis Of Thomistic Thought by Reginald Garrigou-Lagrange, O. P.)

      Since nothing can move itself

      or that?

      an object can only move if its potential to move is activated by something outside of it

      or that?

      Potentiality is necessary, yet not sufficient condition of motion. If it was sufficient, anything potential would automatically actualise itself (and also, in that case there would be no difference between actuality and potentiality). To actually perform a transition from potentiality to actuality, not only the respective potentiality is required, but also a mover that is already in actuality with respect to the quality/quantity to be moved/changed. But, given the principle of non-contradiction, nothing can be both in actuality and in potentiality in the same respect. So nothing can move/change itself, i.e. actualise its own potential to move/change.

      For further discussion, allow me to direct You to Anscombe's replies to Hume's objections to the principle of causality.

      But what makes God different from anything else is that he has no potential to move or change.

      or that?

      God is pure motion itself (or what Aquinas calls act)

      or that?

      Nothing changes God in order to bring about effects in the world. Instead, God brings about effects by his own power.

      or that?

      I believe I've covered all of these questions in my reply to Your other comment below. Although the order of the steps Aquinas takes when proving the existence of God is not quite obvious from the article itself, the demonstration involves proceeding from Pure Act to God, not the other way around.

      (Also, as I said elsewhere, there is an error in the article when it says that motion and act is the same for Aquinas. They are not, as probably evident from my discussion in this comment.)

      Hope this helps. Cheers,
      Andrej

      • Hi Andrej,
        Thanks again for your interesting, informative, and lucid reply!

        One cannot avoid an equivalent of the concept of potentiality, if Parmenides's static universe is to be avoided.

        There are still several problems there. First, why should we feel we must avoid a block universe? Many physicists and philosophers of science find that concept entirely satisfactory. I do also. Second, if the concept of potentiality were accepted, how would we know that it refers to a single universal kind of process for all types of change, both material change as we observe at human scale by our senses and nonmaterial "change" as in a supposedly divine cause for an original mathematical singularity having only a rule describing a quantum field but no matter, energy, or spacetime? Third, why accept Aristotle's solution at all when modern descriptions of change are wholly different than his? We don't reify Aristotelian categories; we reduce to patterns in particles. When we bend a twig, we don't think there is ultimately a real entity called the twig that has changed; not even the atoms change; only the distances between the atoms change, and those distances weren't "beings" in the first place.

        To actually perform a transition from potentiality to actuality, not only the respective potentiality is required, but also a mover that is already in actuality with respect to the quality/quantity to be moved/changed.

        Assuming those categories were granted, what is to be made of the spontaneous appearance and disappearance of virtual particles, or spontaneous radioactive emissions? They appear to many physicists, and to me, to falsify any theory that says Aristotle's categories apply to the real world.

        • Andrej Tokarčík

          Hi, Noah. I'm glad that You enjoyed my previous reply, will do my best this time as well! Once again, You raise some very good questions, and I shall attempt to answer them inline.

          "First, why should we feel we must avoid a block universe? Many physicists and philosophers of science find that concept entirely satisfactory. I do also."

          An examination of the reasons why such a counter-intuitive view may seem satisfactory and justified will probably lead us to the uncritical acceptance of the assumption that the overall working of the universe can be reduced to an abstract mathematical structure. Given that, conclusions like "time/change is just an illusion" emerge quite naturally, as the timeless nature of the mathematical apparatus inevitably becomes restricted by the arrow of time.

          I'm by no means about to deny the usefulness of similar abstractions. But it simply doesn't follow that a useful abstraction can be retroactively declared to be in a one-to-one correspondence with the reality being construed. Such a correspondence is also not possible because the structure abstracted and written in the form of mathematical equations is always just that, a structure, and hence there needs to be something (some real matter?) which has the structure.

          Furthermore, if change is to be removed from the objective reality, the fact that we actually observe the universe to be in a perpetual change is certainly in need of explanation. As already hinted at, this explanation usually resides in relocating the perception of time to the human mind. Well, the mind is certainly mysterious enough to be blamed for all sorts of distortions, but doesn't it feel like too much of playing the mind-of-the-gaps game sometimes? :) Don't we actually expose ourselves to the hazard of making the reality conform to our method, and not the other, perhaps more desirable way around?

          What this takes us into is a kind of dichotomy between the universe and the human mind. Indeed, it is a dualism of the Cartesian form, which has a range of its own well-known problems: the problem of causal interaction, of correlation of mental and neural states, of simplicity and so on. The fact that a changing mind can derive and synthetise any knowledge about the changeless reality has to be especially attended to (unless the physicist doesn't cut off the very branch he's sitting on). And finally, the reason why changes occur in the mind itself has to be explained (which in turn I think requires a kind of potentiality but as mind-dependent rather than objective reality).

          As Edward Feser succinctly put it,

          "But no Parmenidean view is coherent. Change can never be entirely eliminated, but only shuffled around. If you deny it really exists in the mind-independent world, you've still got to deal with it in the mind itself. If you deny it exists even there, you've got to show how that very suggestion is coherent -- which is impossible because the very act involves going though a chain of reasoning, trying to convince someone (even if only yourself) that change is illusory, etc. -- all of which involves change."

          Hope it's enough for now to address Your first question, which I believe can be extended to much broader a scope, virtually indefinitely. Anyway, let's move on!

          "Second, if the concept of potentiality were accepted, how would we know that it refers to a single universal kind of process for all types of change, both material change as we observe at human scale by our
          senses and nonmaterial "change" as in a supposedly divine cause for an original mathematical singularity having only a rule describing a quantum field but no matter, energy, or spacetime?"

          I don't think it is correct to view potentiality as a process. Potentiality is rather a capacity/capability that a thing can attain -- it is not concerned with how of a thing's change but the why of the change's mere possibility. If we deny that there are some other ways in which a thing can exist as opposed to the way in which it exists now, then of course no change is comprehensible. Potentiality (what-can-be) as an objective midway between what-is and what-is-not is a minimal explanation of the sense datum of change.

          Of course, none of this has anything to do with non-material things. Aristotle isn't worried, though, because the presence of potentiality in material things on their own points to a Pure Act (the supposedly "divine being"), which, however, can't undergo any change at all precisely because of its being a Pure Act -- the thing would have to have some potential in order to change, but in that case it could not have ever been a Pure Act.

          "Third, why accept Aristotle's solution at all when modern descriptions of change are wholly different than his? We don't reify Aristotelian categories; we reduce to patterns in particles. When we bend a twig, we no longer imagine there is ultimately a real entity called the twig that has changed; not even the atoms change; only the distances between the atoms change, and those distances weren't "beings" in the first place."

          As I already tried to explain above, the doctrine of potentiality doesn't deal with the concrete mechanisms of change. Instead, it is to give a reason why there is any change at all.

          In Your example of the twig, even if we grant that a twig is completely reducible to a set of atoms (and perhaps their interactions), there is always an inherent presupposition of real potentiality: if the atoms didn't initially have potential to be in a different location (which in turn results in a modification of their mutual distance), it makes no sense to say that the atoms changed their location, or even that "patterns in particles" may be taken advantage of to account for change. You're right that distances aren't beings, but the atoms themselves did change with respect to their location in the spacetime, if nothing else -- the location is a real attribute of an atom (as any other material being) and as such it is indeed reasonable to say that the atoms changed.

          That's why I think a variant of potentiality effectively giving rise to "sets of possible states" is always required to account for any real change.

          Assuming those categories were granted, what is to be made of the spontaneous appearance and disappearance of virtual particles, or spontaneous radioactive emissions? They appear to many physicists, and to me, to falsify any theory that says Aristotle's categories of potentiality and actuality apply to the real world.

          This is a very common question, although it is usually directed against the principle of causality. The spontaneous phenomena in no way undermine the notion of potentiality. For if there weren't potentiality involved, there would be no phenomena at all, neither appearances, nor disappearances, nor emissions. All of those would just "be" instead of "become to be". Without potentiality, we would not be able to observe their becoming, that is, their transition from what-can-potentially-be to what-actually-is.

          Now, regarding the principle of causality, I often imagine whether the medievals weren't challenged, too, since in their time for instance the sudden appearances of various light displays in the sky could be seen as spontaneous or inexplicable as quantum events are today. As far as I know, there is nothing that could at this point be said for the principal impossibility of the existence of a more fundamental cause of these occurrences.

          One the other hand, we obviously see that even fundamental particles or what-not are composites of potentiality and actuality (for they can change), then if we're committed to the principle of causality, we are forced to admit the existence of the more fundamental cause. I hope I'm not going too far to say that since material things are ontologically more complex than immaterial things (inasmuch -- according to the Aristotelian-Thomistic understanding, at least -- the material things are composed of matter and form conjoined by their existence, while immaterial things are form only plus their existence), this more fundamental cause may very well be immaterial, and therefore outside the reach of physics.

          To conclude, I'd like to quote a relevant passage from Feser's Aquinas (pp. 54-55):

          "It is also sometimes suggested that quantum mechanics undermines the principle of causality insofar as it implies that the world is not deterministic. But the Aristotelian does not regard the world as deterministic in any case [...] and thus does not hold that every cause must be a deterministic cause. As the analytical Thomist John Haldane has noted, if we can appeal to objective, non-deterministic natural propensities in quantum systems to account for the phenomena they exhibit, this will suffice to provide us with the sort of explanation the Aristotelian claims every contingent thing in the world must have."

          Cheers!
          Andrej

          P. S.: I'm sorry that it took me so long to reply. I'm going to reply in the other thread of our discussion soon!

          • OK, I'm back. Work sent me to the Florida keys for once instead of frozen northern lands, and consequently I chose not to bring a laptop. :)

            Your response on the block universe got rather carried away in its syntax and I can't confidently draw out the intended meaning.

            You suggested that there's something mysterious in how, in the block universe (a.k.a. the B Theory of time), the appearance of change is from the brain's perspective. You didn't spell out what the mystery would be, though. I don't know where else besides the brain the appearance of change could be located under any theory. Most scientists and philosophers prefer the B Theory, which I think is adequate reason (as a non-expert) to believe that it is overall less mysterious than the A Theory, as well as a more intuitive match to our universe's physics.

            The physics are more problematic to me than the philophers' concerns as described at the Stanford link. I personally can't envision how an A Theory would work since under established physics there is no unique ordering to events. The temporal sequence of events that are separated by a distance depends on your frame of reference, and even events located at the same point in space and involving the same particles sometimes have no uniquely correct order in which they occur, due to quantum effects. If there's some "flow" of time that is real in a way the past and future aren't, then there's a different local flow in every place for every frame of reference and they've still got some crazy branchings, mergings, and whirlpools.

            A line that you wrote suggests to me that the way you envisioned a block universe is different in a key regard from how its advocates describe it.

            And finally, the reason why changes occur in the mind itself has to be explained

            You later quote Feser who, if he is taken as addressing the B Theory when he referred to a "Parmenidean view", give an objection that is incoherent as it apparently relies on the same incorrect vision of what the block universe model says. In the block universe model there are no changes in anyone's 4D brain state, just as there are no changes in any 4D state anywhere in the universe. The commonest analogy is frames of a movie. All the frames physically exist equally and no frame changes into another, with only the story as an abstraction proceeding from one to the next. At each place along its timeline, the brain has memories of its past (the previous 5-ish seconds in short term memory and the more distant past in long term memory), perceptions of its present, and expectations of its future, and that's all that is needed to account for experience of time. Brains have different states, including different beliefs, at different times in a block universe, but there's nothing ontologically special about any particular moment or any particular path through the 4D block.

            You're right that distances aren't beings, but the atoms themselves did change with respect to their location in space, if nothing else -- the location is a real attribute of an atom (as any other material being) and as such it is indeed reasonable to say that the atoms changed.

            If we speak more precisely, this starts to look very strange. There's no privileged frame of reference in space, and presumably I'm moving the twig about as I handle it anyway, so no, the location of an atom is not one of its attributes. So you have to say, not that the atoms have a "potential to be a different location", but that the atoms would have a potential to be a different distance from other atoms. Clearly the distance between a pair of atoms is not a property of either one of the atoms; it's a property of the set of atoms. While we say the atoms have a physical existence, the set of atoms has only an abstract existence. So for bending a twig we still have no need to suppose there was any change in a physically existing thing.

            Now, regarding the principle of causality, I often imagine whether the medievals weren't challenged, too, since in their time for instance the sudden appearances of various light displays in the sky could be seen as

            I think you got cut off. There's probably a length limit.

          • Andrej Tokarčík

            Hello, Noah, welcome back! Hope You enjoyed the trip! :) I don't know what's going on with the length limit, I see the comment posted in full. I'll try to keep more to the point this time.

            First of all, I'd emphasise that the B-theory is a philosophical construct, even though it may find its inspiration in physics. At the end of the day, what is solely relevant when evaluating a physical theory is whether it can correctly predict various numerical characteristics whose actual values are obtained by measurements -- the philosophical considerations that informed the development of the theory still remain philosophical, though. As such, any interpretation of physical theories with regards to ontology etc. is open to philosophical criticism. In addition, the fact that there are alternatives more or less equivalent to the theory of general relativity which could lead to completely different philosophical conclusions (MoND, for instance) might be also of interest.

            Next, I'm not arguing against the B-theory and I don't understand Feser to be doing so either. The matter is not whether the A-theory rather than the B-theory holds, but whether change is real -- and for what it's worth, I don't see the B-theory to imply that the reality of change is to be completely abolished. All that the B-theory (or more generally, eternalism) entails is that all points in time have the same ontological states and that time is a full-fledged real dimension.

            However, the reality of change can be still established under these conditions because even if things are considered to be temporally extended objects, this does not explain why our concious experience is not altogether bound to a single time point. That is, when You say that "Brains have different states, including different
            beliefs, at different times in a block universe", the mere existence of these states doesn't give a reason why it seems that our brains acquire those different brain states consistently in a certain sequence rather than having them all together. It appears as though there has to be something (outside the block universe) causing that sequential movement along the time dimension of the block universe with respect to particular frames of reference -- which obviously doesn't amount to an elimination of change, the change just got moved up to a higher level.

            Moreover, I don't think that the absence of a privileged frame of reference leads to the impossibility of change. Just as it was possible to give a justification for all accepted scientific theories without a privileged frame of reference, I think that to observe change even within a single frame of reference would demand an explanation, which needs to be given in terms of actuality/potentiality. Especially when one realises that observation is a kind of change, the whole enterprise of empirical science gets compromised when it is not necessary for observations to reveal new information about the reality (the results of observations could just be eternally stored in our brain states, whether they correspond to the real thing or not).

            I'm also not aware of anything that would preclude potentialities of things to be formulated in relational terms involving other things. I don't think Your argument about the set's not having a physical existence counts because the members of the set have a physical existence.

            Last but not least, change doesn't have to be taken as a process, rather, a thing can be said to be in change whenever it has certain attributes which the thing doesn't have necessarily of itself. For instance, if the same thing is observed to have some different attributes at some distinct time points, the thing will surely not have the attributes necessarily of itself without other influence. In such a case, an external factor (a changer) is required which causes that attribute to be the way it is at each of the considered time points. This view of change actually appears to have been preferred by Aquinas (cf. the "product" interpretation).

            Best,
            Andrej

            P. S.: Could You please back up Your claim that most scientists and philosophers prefer to approach time as the B-series?

          • I'd emphasise that the B-theory is a philosophical construct, even though it may find its inspiration in physics.

            Indeed. Most any philosophical account of time can be made compatible with scientific models, so I don't claim that the science rules out the A-theory. I merely claim, for the reasons given in the previous comment, that physics under the A-theory is almost too strange to imagine, whereas under the B-theory it remains conceptually simple.

            I don't see the B-theory to imply that the reality of change is to be completely abolished.

            In the block universe model, time is another dimension like the three of space, and an object extended along its timeline "changes" from its past to its future in the same sense that an object extended along its line of lattitude "changes" from its east side to its west side. That is to say, there is no process of physical change there, only changes in abstractions (such as the perceived difference between two spatiotemporal cross-sections of the object).

            this does not explain why our concious experience is not altogether bound to a single time point. ... why it seems that our brains acquire those different brain states consistently in a certain sequence rather than having them all together.

            Consciousness is a feature of a brain state. You at 4PM today have a different brain state than me at 4PM today (a spatial difference) and than you at 4PM yesterday (a temporal difference), so among those there are three different brain states conscious of three different sets of things. My brain state at this moment includes consciousness of the contents of my brain's short-term memory systems, which includes about the previous five seconds of sensory data. My brain state of the temporal cross-section of me 2 seconds later includes in its short-term memory systems about the previous five seconds of its sensory data, 3 seconds of which overlap with the first temporal cross-section of me. That sort of overlap is how brains maintain continuity in their sense of self and the abstracted sense of flow in the things happening around them.

            change doesn't have to be taken as a process, rather, a thing can be said to be in change whenever it has certain attributes which the thing doesn't have necessarily of itself. For instance, if the same thing is observed to have some different attributes at some distinct time points ...

            For clarity, we can use he example of the twig, and we say it had at one time point the attribute "not bent" and at another point the attribute "bent". But as already pointed out, such attributes do not belong to any physical part of the twig. They're just associations that our minds have with different perceptions; my brain state at the first time point includes me seeing an unbent twig and recognizing that it is unbent, and my brain state at the second time point includes me seeing a bent twig and recognizing that it is bent. My brain state at the second time point is a different thing than my brain state at the first time point, so it is not the case that different attributes are assigned to the same thing at different times. Real changes aren't needed in an account of reality.

            P. S.: Could You please back up Your claim that most scientists and philosophers prefer to approach time as the B-series?

            View the second page for an insider's perspective on the philosophy side. However, the survey discussed in brief here suggests that there's much less consensus among philosophers generally once we get away from specialists in the subject. Similarly, for lack of evidence I'll have to retract the generality of "scientists" (who probably mostly don't think about it) and only point out its popularity among physicists.

          • Andrej Tokarčík

            Noah, thank You for the response to my P.S., I very much appreciate it.

            That is to say, there is no process of physical change there, only changes in abstractions (such as the perceived difference between two spatiotemporal cross-sections of the object).

            But don't the changes in abstractions themselves demand an explanation? Why is a spatial object extended from its east side to its west side precisely in the way it is? Why is a spatiotemporal object extended throughout the block universe in the way they are? Those sound like perfectly legitimate questions to me.

            To give an illustration of what I'm hinting at, suppose that the universe is not a four-dimensional space, but a one-dimensional one (i.e., a "line-world"). Given that the sole dimension is specified by real number coordinates, there is an (uncountably) infinite number of zero-dimensional spaces (i.e., "point-worlds"). For simplicity, let's suppose that there is only a single type of a point (that is, that there is no difference between, say, colourings of the points or the like). Then each of the infinitely many zero-dimensional spaces is in two possible states:

            (i) either it contains a point,
            (ii) or it is empty (devoid of a point).

            However, if the 1D space (= the supposed universe) contains at least one 0D space satisfying (i) and also at least one instance of (ii), then (i) and (ii) are not only possibilities, but also potentials -- it is not only logically possible for a zero-dimensional space to have the other property (that would entail only possibility), but possible even physically, according to the laws of nature of that universe (this implies real potentiality). In that case, though, it is quite reasonable to ask why each particular 0D space has its corresponding potentiality actualised instead of the other potentiality. Thus, the 1D block universe would consist of changing things. (Recall that when a thing is in a state of an actualised potentiality, then Aquinas would say that the thing is changing.)

            I hope that You see how this thought process could be easily extended to a 4D block universe -- as long as the 4D space has at least two different 3D slices, which I believe is not a controversial assumption with our block universe. In this sense, I think there are actualised potentialities even in the block universe, which is enough to lift off Aquinas's First Way.

            That sort of overlap is how brains maintain continuity in their sense of self and the abstracted sense of flow in the things happening around them.

            Why are the overlaps necessary? Even if there were none, how would I notice? There is no way for me to recognise that short-term memories of my different brain states don't overlap because all data available to me are determined by my current brain state; I can't intentionally "bring" any information from the preceding temporal cross-sections to be checked against which would show inconsistencies with my previous thoughts/actions since the current brain state alone "dictates" what I remember. To rely on the overlaps seems redundant.

            I'm also wondering whether there could be a temporally non-extended body/person (existing at a single time point only) which would have conscious thoughts of time's flowing -- i.e., whether it is possible for the person's only brain state to contain/generate enough memories and expectations for the future so that the person would think that the continuity of the person's self has been preseved, that time flows and that physical change is real.

            If not, then the illusion of change according to the B-theory of time would remain unexplained. If yes, then the brain turns out to be quite tricky, opening up many questions, for instance: Isn't it the case that the brain actually deceives us more than helps us? Can't the brain as well entice us into believing this objective reality stuff instead of properly acknowledging that all of it is just mind-dependent?

            My brain state at the second time point is a different thing than my brain state at the first time point, so it is not the case that different attributes are assigned to the same thing at different times.

            It appears to me as though at first You were concentrating on an overtly restrictive notion of "physical change" but then all of a sudden You had no problem to prefer a very loose meaning of "thing" in the quoted passage. Your brain state is not a physical thing -- Your brain is. And it's brain which is in different states at different times. Thus, there is a difference in the observer when seeing a bent twig in comparison with a time of seeing an unbent twig.

            Or are You suggesting that my brain is never the same thing either? How come that I am a temporally extended object then? Furthermore, why do You think that the time dimension should be an ordered sequence? If there is no connection between the 3D slices associated with individual time points, they wouldn't have to be put in a linked time sequence at all, would they?

            By the way, I'm very grateful for this discussion. I think I'm learning a lot. Thanks!

            All the best,
            Andrej

          • Oh, I see the rest of the comment now. Perhaps there was a glitch in Disqus when they rolled out their new Dashboard. I'll edit this comment to respond to the part I missed after I've had a chance to think about it.

  • Likewise, there must be an “uncaused cause” that sustains the elaborate chain of simultaneous causes in our universe. We call this uncaused cause God.

    As has been pointed out countless times and must be pointed out again, this definitional tactic is fallacious. If I granted the argument up to that point (which I don't, because it makes all sorts of unjustified assumptions), I could equally well decide to call this uncaused cause Santa Claus, and then claim I'd proven the existence of Santa Claus. Without specific evidence we are unjustified in saying the "uncaused cause" has any other properties. Just giving it a name isn't evidence that it has the properties associated with that name.

    • Andrej Tokarčík

      Hello, Noah. It is perhaps too typical for defenders of Aquinas's arguments to act as though the Five Ways alone do establish God's existence. What the Ways do is to show that there exists something in the universe with the properties that are usually attributed to God. That is related to the fact that, according to Aquinas, it is impossible to start with a definition of God -- all we've got when approaching the question is an approximate notion of God, which in this case includes the idea of God's being the source of all things. As such, we have no other choice when trying to figure out if such a source of all things exists, but by examining the things and phenomena that we can observe in the world, and seeing whether they all do actually happen to be effects of the same cause in some sense. It is in this aspect only that Aquinas is able to conclude the First Way with the seemingly arrogant and fallacious "and this everyone understands to be God", which should perhaps be read as "what this argument establishes is the existence of a being with a property that is usually attributed to God".

      If the Five Ways failed, it would imply that even something corresponding to the assumed incomplete idea of God hasn't been shown to exist, and thus God with the other usual properties added (such as omnibenevelonce, omnipotence, omnipresence) cannot be said to exist either. But if the Ways are successful, we are able to do some further investigation regarding what the other attributes of this cause demonstrated by the Five Ways are.

      And this is exactly what Aquinas did, as he he devoted several hundreds of pages in Summa Theologica and elsewhere to demonstrate that Pure Act and/or Being Itself (whose existence follows from the Five Ways) must be also unique, immutable, immaterial, eternal, infinite in power, perfectly good, simple and so on.

      Certainly, just because Aquinas wrote on these topics, it doesn't automatically mean that his reasoning is sound. However, it does show that Aquinas didn't push forward any kind of unjustified name-calling, as is sometimes claimed by the other side of the debate. Furthermore, if Aquinas's arguments proving the divine attributes are correct, it cannot be "equally well" decided that Pure Act should be referred to as Santa Claus, for Santa Claus is usually not meant to possess (some of) the divine attributes.

      All the best,
      Andrej

      • I see no reason that "we have no other choice when trying to figure out if such a source of all things exists,"

        Why can't we just accept that there may be limits to what we can know about origins? I think theoretical physicists and astrophysicists are doing a great job of following where the evidence leads in this regard. I do not have the education to follow what they have already discovered, but it seems a much better plan than trying to extrapolate based on logic and intuition.

        • Andrej Tokarčík

          The trouble with the approach of putting limits on what we can know is that most of such boundary-making is arbitrary. You say that there are limits when talking about origins, but in turn I may choose any controversial topic and consequently say that the discussion is insoluble and thus that there are limits when talking also about quantum physics (recall Mermin's "Shut up and calculate"?), evolution, law, politics, environmental issues, human rights (who dares to know anything about that!), common sense or ban all certainty in the domain of human knowledge altogether. Especially, I could say that if we're talking limits, I'll put a limit on what we can put a limit on and I especially don't like that limit of Yours! Seems to lead to a kind of a deadlock, doesn't it? :)

          Also, why would science be an exception to the rule of not talking authoritatively about origins? It's clear that science has its own philosophical presuppositions (not to talk about scientists), why wouldn't extrapolation of these logical assumptions undermine their discoveries?

          • I didn't say there were limits, i said there may be. My thinking is that because we are looking into an incredibly difficult area of physics to understand that it is by no means necessary for us lay folk to reach conclusions about this. We are trying to make ontological and epistemological conclusions about realms in which time and space do not exist. The danger of reaching conclusions based on ignorance is very high.

          • Andrej Tokarčík

            That is a very good point, sorry that I put words in Your mouth. I'm just wondering whether there is a risk at all of adhering to the truth of "it is dangerous to make any conclusions about realms beyond time and space" so much that the proposition itself would become enduring enough to count as a conclusion regarding realms beyond time and space (and effectively a limit against which I objected before).

            I think that such a conclusion may be legitimately reached once it is proven "sufficiently" rationally defensible as well as having "sufficient" explanatory power. The only different aspect of the respective argument in comparison to explanations of phenomena that can be easily/directly verified/observed is that it must be obviously put under more scrutiny. But still, the possibility of a proper metaphysical* explanation of origins cannot be trivially precluded.

            As You may now see, the answer "there may be limits" makes actually a very poor objection against an existing explanation of the kind meeting the criteria. If one discovers such an explanation, he shouldn't hesitate to accept it, because accepting the explanation is not an irrevocable act, after all. If the explanation is later found lacking (containing an error or after confronting another more adequate framework), it can and should be abandoned.

            And finally, I think that the adherents of the "there may be limits and I'm not in a position to choose" stance do too commonly implicitly accept the conclusion of "there is nothing beyond time and space" or "there are limits regarding our knowledge in this respect", the first of which is a conclusion initially said to be avoided, with the other being a (seemingly) arbitrary limit.

            Such an agnosticism appears to me to be untenable in the long term, anyway, given that throughout the human history great many metaphysical explanations of the existence of the universe have been proposed that should be evaluated, and also due to the fact that apparently there is no metaphysical consensus (in contrast to scientific consensus) to be waited for to make a decision.

            All the best,
            Andrej

            _____
            * - I believe that physics cannot have a final word on the related questions, as it is the study of the behaviour of matter in space and time. Thus, physics is not even in principle able to handle questions that go beyond space and time and so we must resort to a more fundamental science (in a very loose sense of the word) and its toolbox.

        • Jimi Burden

          The Buddha called the quest for origins a complete waste of time which will lead "to a thicket of wrongs views." After 2500 years, it's difficult to see otherwise.

      • Hi Andrej,
        Thanks for the thoughtful reply. I'll respond in turn to some points; if I pass over something you wrote without comment, I probably agree, and as if we were in a face-to-face conversation you can imagine me nodding along until I get a consterned look on my face at some points.

        What the Ways do is to show that there exists something in the universe with the properties that are usually attributed to God.

        I don't think that all Five Ways are valid, but even on the assumption that they were valid, it wouldn't follow that any pair of them are referring to the same entity.

        That is related to the fact that, according to Aquinas, it is impossible to start with a definition of God -- all we've got when approaching the question is an approximate notion of God, which in this case includes the idea of God's being the source of all things.

        There are more and less useful senses of "definition". One sense is that a definition of X is a complete description of the truths about X. Clearly no such definition of God could be given. Similarly, no such definition of arithmetic could be given either. A better sense is that a definition of X gives only adequate description to distinguish X from all other entities. The Peano axioms do this for arithmetic. It ought to be possible to give this kind of definition for God as well. The mundane sense is that a definition of X gives adequate description to distinguish X from the other entities in its usual context. Dictionary definitions and intuitive grokkings of words during conversation work this way. For example, it's not possible to give necessary and sufficient conditions for "man" versus "woman", but this presents no obstacle for recognizing the gender of 99% of people we encounter. People who already believe in God generally use this sense of defining "God" when they talk to each other. And for atheists, that mundane definition is likewise the "God" that we don't have a belief in and that the Five Ways do nothing to address.

        The Five Ways would have a chance of being useful if the second, "logical pinpointing" kind of definition of God were given and shown (either logically or with evidence) that it entailed the third, mundane kind of definition.

        In short, believers trying to prove the existence of their God don't get to assume that the "God of the Philosophers" and the "God of Abraham, Isaac, and Jacob" are the same. Proving the first, if it could be done, would do literally nothing to prove the second.

        as he he devoted several hundreds of pages in Summa Theologica and elsewhere to demonstrate that Pure Act and/or Being Itself (whose existence follows from the Five Ways) must be also unique, immutable, immaterial, eternal, infinite in power, perfectly good, simple and so on.

        OK, I've only read the Summa and not the other documents, but the most common failing of the Summa that bothered me were the bait-and-switch definitions. See A Human's Guide to Words, especially "The Parable of Hemlock", "Words as Hidden Inferences", and "Extensions and Intensions", though most of them are short and helpfully clarifying. What I see going wrong is like that parable. Insofar as words like "perfectly good" and "simple" are proven to apply to "Pure Act", they can't validly lead to the ordinary inferences we like to make from those words; and if we instead start by using the ordinary inferences of words, then the Scholastic proofs are entirely invalid.

        • Andrej Tokarčík

          Hello again, Noah, it's always pleasant to imagine human reactions (the nodding & consterned look) beneath the received binary sequences, thanks for them :)

          I don't think that all Five Ways are valid, but even on the assumption that they were valid, it wouldn't follow that any pair of them are referring to the same entity.

          Certainly, it wouldn't follow automatically. But all of the Five Ways can be seen to point to a being that is subsistent existence itself (i.e., nothing but existence), if not directly, then by a trivial extension. For instance, let's suppose the First Way is successful, hence the Pure Act exists. The Pure Act is either existence itself or existence plus some other acts (where existence is understood to be a kind of act upon which all other acts depend; it is incoherent to think of a being that is somehow actual that does not exist at the same time). In the first case, what is obtained is already existence itself. In the other case, the Pure Act is a nontrivial metaphysical composite. But composites are less fundamental than whatever principle accounts for their composition. Thus the existence of such a Pure Act demands an explanation and in turn presupposes the existence of an utterly simple Pure Act, which is subsistent existence itself.

          Now, why should we think that subsistent existence is unique? Because there is no way to distinguish more than one, even in principle! If there were such a way, one such thing A would have to have something the others do not, in which case A is not existence itself, but instead existence plus some act or potency, because of which the things could be known from each other. Also, any such thing cannot be individuated by matter because then it would be material existence (dependent on matter for its being) rather than subsistent existence. (Cf. Feser's Aquinas, p. 30.)

          As all the Five Ways refer to subsistent existence itself and subsistence existence itself must be unique, the Five Ways do indeed lead to the same entity.

          In short, believers trying to prove the existence of their God don't
          get to assume that the "God of the Philosophers" and the "God of
          Abraham, Isaac, and Jacob" are the same. Proving the first, if it could
          be done, would do literally nothing to prove the second.

          Oh, how come they don't? Are You saying that if the existence of the God of the philosophers was proven it wouldn't change the perspective at all? In my opinion, it certainly would -- at least the debate would shift from atheism vs. theism to the domain of weighting the various brands of theism (with purely philosophical theism still remaining an option, of course).

          I think that once the existence of divine Being is established, one becomes much more open to evidence and testimony that she would have previously dismissed almost automatically in the course of applying the skeptical attitude of "once you eliminate the impossible, whatever remains, no matter how improbable, must be the truth", which even "just" with the God of philosophers (that is, the intelligent supreme being that conserves all existence and constantly directs all nature) gets put into an entirely new light. For instance, shouldn't the prior for the possibility of Christ's resurrection increase at all? Or, doesn't the name YHWH (cf. Exodus 3:14) fit in with the notion of subsistent existence itself in any special manner?

          At this point, I'd quote Edward Feser once again (from here, the article is not of particular interest to the ongoing debate):

          "Consider that for at least some classical theists, philosophical
          arguments alone can tell us not only that there is a God, but also that
          human beings have immaterial and immortal souls. For Thomists, they tell
          us further that the soul is related to the body as form is to matter,
          so that though the soul survives the death of the body, the human person
          does not, and can come to life again only if soul and body are
          reunited; that the soul cannot arise out of the material processes that
          suffice for the generation of lower animals but must be specially
          created by God with each new human being; and that our natural end is
          God Himself, so that we cannot be happy apart from Him. Now, that there
          will indeed be a resurrection of the dead, as well as the details of the
          Christian account of salvation, are further facts that cannot be known
          apart from divine revelation. But what (many) classical theists regard
          as knowable through reason alone and apart from specifically Christian
          theology already suffices to show that God has a very special interest
          in man indeed – so much so that He specially creates each individual
          human soul for a natural end that involves knowing Him everlastingly, in
          a way that requires a further divine intervention in the form of a
          resurrection if it is perfectly going to be fulfilled. It can hardly be that surprising, then, that the God of the philosophers and the God of Abraham, Isaac, and Jacob turn out to be the same."

          Besides, even "just" with the God of philosophers, I can imagine the sheer experience of genuinely talking about God instead of
          whether
          there is one may turn out to be surprisingly strong. And if we should
          come to hold, as the "pagan" Aristotle famously did, that we can reach fulfillment when
          contemplating God's existence, we may eventually get the experience
          of being led by Him. Faith, after all, must be a gift, a real virtue,
          and cannot be a human merit. At the end of the day, the deductions and arguments are
          nothing more than preambula fidei.

          Perhaps irrelevant, but I'll just reiterate what I said elsewhere: that the whole "project" of whether there is God should be seen as advancing in stages. It is not all or nothing, "either there is a real chance of becoming a Catholic or I won't bother at all". The Five Ways should be studied not inasmuch as they confirm the truth of a whole religion, but so that we properly exercise our intellectual powers, shun ignorance and comply with the epistemic duty of having as many true beliefs as possible. Having said that, the question of "But what if the Five Ways won't prove Catholicism?" is not quite an appropriate starting point. :)

          See A Human's Guide to Words,
          especially "The Parable of Hemlock", "Words as Hidden Inferences", and
          "Extensions and Intensions". (The whole series of posts are short and
          helpfully clarifying, so I recommend those too when you have time for
          them.) What I see going wrong is like that parable.

          Thank You for the links, I'll definitely go through the series -- although I've got time just to quickly read the parable so far. As such, I apologise upfront in case I'll be misrepresenting Your or Eliezer's positions.

          First, I'd like to mention that I consider the principle of non-contradiction to be absolutely certain, even on the ontological level, as it cannot be coherently denied. As such, there is at least some eternal knowledge that "the Greeks were so fond of", which we cannot simply get by without even today.

          Second, I think it is a mistake to approach all generalisations as though a single counter-example would suffice to refute them. We better don't generalise about generalisations and differ between strict and loose generalisations :) I'd say that Aristotelian categoricals such as "All men are mortal" or "Dogs are four-legged" should be understood in the loose sense, that is as conveying a norm, a natural tendency, in which case obviously these statements cannot be taken together as a check-list to infer an individual's necessary membership in a class. Hence, I'd still be able to say that dogs have four legs without any qualification even though I know that my neighbour's poor pet's got only three. Even more, I'd still be able to say that it is part of the essence of a dog that dogs are four-legged.

          Third, I'm wondering whether You're not painting with too broad a brush here. It is perhaps too easy to dismiss a framework for its use of words, or for its advocation of the objective truth (as seems to be the general postmodernist atmosphere).

          Insofar as words like "perfectly good" and "simple" are proven to apply
          to "Pure Act", they can't validly lead to the ordinary inferences we
          like to make from those words; and if we instead start by using the
          ordinary inferences of words, then the Scholastic proofs are entirely
          invalid.

          I think the following is a good general answer regarding the possible misuse of words. It deals with analogical notions that Aquinas used as a middle ground between the equivocal and the univocal (copied from here):

          "Now when the
          Thomist says that the words we apply to God cannot be understood in the same
          sense in which we apply them to human beings, he does not mean that such
          language must always be understood metaphorically or non-literally. Some
          of it should be, but some of it should be understood in a way that is literal,
          but analogical rather than univocal.
          Now, when we speak of God as “getting
          angry” or “being moved to pity” or
          the like, that is mere metaphor, because it implies a change in God and God
          cannot literally change. But when we
          speak of God’s goodness, love, intellect, power, will, etc. that talk is to be
          understood not metaphorically but
          analogically. That means that the
          description is literal, but just not
          univocal. We are saying that there
          literally is goodness, love, etc. in God and that while it is not exactly the
          same thing as what we call goodness, love, etc. in us (just as the goodness of
          pizza is not the same thing as the goodness of a man) it is nevertheless
          analogous to what we call goodness, love, etc. in us."

          In short, it is not said that God has power, goodness, etc. in exactly the same sense in which we apply the terms to ourselves, etc., but that there is in God something that is analogous to power, something analogous to goodness, something analogous to intellect, and so on, and that these "somethings" all turn out to be one and the same thing (due to divine simplicity). See Feser's Aquinas, p. 128.

          Of course, much more could be said on the topic, since it is indeed important. But I guess a full account would require a book written by a proper Thomistic philosopher rather than a comment by an enthusiast :)

          All the best!
          Andrej

          • For instance, let's suppose the First Way is successful, hence the Pure Act exists. The Pure Act is either existence itself or existence plus some other acts (where existence is understood to be a kind of act upon which all other acts depend; it is incoherent to think of a being that is somehow actual that does not exist at the same time).

            OK. If we define "existence" in that way, though, how do we know it corresponds to how existence really works? There are many alternative definitions one could give, and without empirical tests there we have very little justification for privileging any one definition. Maybe existence as it really works is about 17 different kinds of "acts", one for each type of fundamental particle. (Or this cuter version if you prefer. :D ) That'd be a form a physicalism. Or maybe existence as it really works is not any "act" at all, but just the principle of bivalence, so that every internally coherent structure exists. That'd be a form of Platonism. The point here is that we can't just pick any definition that works and run with it; we are only justified in defining "existence" as we have good reasons to believe it to be.

            The rest of the section including the above quote depended on that definition, so since the definition was unjustified the conclusions were also.

            Proving the first, if it could be done, would do literally nothing to prove the second.

            Oh, how come they don't? Are You saying that if the existence of the God of the philosophers was proven it wouldn't change the perspective at all?

            If it were proved that the God of the Philophers existed, that would increase my subjective probability in favor of the God of Abraham, Isaac, and Jacob according to the usual Bayesian calculation. So I'll grant that in the scientific sense of "prove", proving the former would do something to help prove the latter. But in the logical sense of "prove", no, it wouldn't help at all.

            At the end of the day, the deductions and arguments are nothing more than preambula fidei.

            The view of the doctrine from this side, as you no doubt recognize, is that it is a clear admission that there are no rationally adequate reasons for belief. :)

            the whole "project" of whether there is God should be seen as advancing in stages...

            Oh, agreed entirely. That's all the more reason that an argument like the First Way, and reconsiderations of it like this page's article, should not attempt to bypass the intervening stages with a flippant "and this all men understand to be God".

          • Andrej Tokarčík

            Noah, I didn't intend to give a definition of existence. If one accepts the actuality/potentiality distinction, I think it follows quite clearly that it is incoherent to say of an actually existing being that it has existence only potentially, regardless of "how existence really works". Thus, the existence of an actually existing being must be said to be an act.

            But in the logical sense of "prove", no, it wouldn't help at all.

            Well, what is Your reason to reduce the sense of "prove" to the solely "logical"? I don't see why it is required to stick with the same method along the whole way. To the contrary, I think that a proof of God of Abraham even in the non-decisive, "scientific" sense would make quite a convincing case.

            The view of the doctrine from this side, as you no doubt recognize, is that it is a clear admission that there are no rationally adequate reasons for belief.

            I'm in no way an utter rationalist (see [1], the 2nd sense) and thus I don't think that every true proposition can be demonstrated to be so by reason alone. However, I think that the authority of the Catholic Church can be rationally justified ("scientifically", not "logically") and as such it is rationally adequate to hold certain truths that the Church teaches on faith. Faith as a source of knowledge ends up to be supra-rational, not irrational.

            Cheers,
            Andrej

          • Noah, I didn't intend to give a definition of existence. If one accepts the actuality/potentiality distinction ...

            Though you didn't intend to define existence, the argument you presented regarding why the Pure Act must be unique still depended on a very specific definition of existence, and it is not clear that that definition is justified. Materialists may reject a unique act of existence and instead prefer that each fundamental particle be considered a distinct kind of act of existence; I personally reject that we even know there to be a difference between existence and nonexistence, preferring (until there is evidence otherwise) to suppose that the principle of bivalence is enough and that everything "possible" is equally "actual".

            I think that a proof of God of Abraham even in the non-decisive, "scientific" sense would make quite a convincing case.

            Indeed, I expect that is the only important kind of case. It's what I was hoping to find on SN. I expect that logical attempts to prove the existence of God will probably always falter by relying on definitions that are not known to actually apply to the real world.

            Faith as a source of knowledge ends up to be supra-rational, not irrational.

            I don't think "supra-rationality" is real. If there are sufficiently good reasons to believe, then belief is rational. If there aren't, then belief is irrational. "Supra-rationality" would need something better than good reasons, which just sounds like nonsense.

    • "As has been pointed out countless times and must be pointed out again, this definitional tactic is fallacious. If I granted the argument up to that point (which I don't, because it makes all sorts of unjustified assumptions), I could equally well decide to call this uncaused cause Santa Claus, and then claim I'd proven the existence of Santa Claus. Without specific evidence we are unjustified in saying the "uncaused cause" has any other properties. Just giving it a name isn't evidence that it has the properties associated with that name."

      Thanks for the comment, Noah. However, this attempted refutation has also been refuted "countless times and must be pointed out again." You're simply playing word games, subbing the name "Santa Claus" for the name "God." Yet this does nothing to refute Aquinas' argument or the conclusions that necessarily follow.

      One of two scenarios are possible:

      First, you're attempting to argue that the cosmological arguments can plausibly lead to Santa Clause as the first cause of the universe, if Santa Clause is understood as we traditionally have: a fat, jolly man who delivers presents at Christmas time. Yet this is impossible for many reasons. I'll just list one. The cause of the universe--by which we mean all space, time, energy, and matter--must transcend the universe. It must necessarily be spaceless, timeless, and immaterial. Yet Santa Clause is none of these things. Because he occupies space, time, and matter, he is a contingent being--his existence depend on other things which in themselves demand an explanation. This, of course, is not true for God, who as the spaceless, timeless, immaterial ground of being is self-existent and therefore non-contingent.

      Second, perhaps you're attempting to argue that the cosmological arguments can plausibly lead to Santa Clause as the first cause of the universe, but by "Santa Clause" you're referring to a cause of the universe that is identical in every way to God except you're calling him by a different name. As explained of, this is insignificant word play and it does nothing to change the strength of Aquinas' argument.

      Hopefully this will definitively end the "but the cause could have been Sant Claus" reply.

      • Thanks for the comment, Noah. However, this attempted refutation has also been refuted "countless times and must be pointed out again."

        Could you link to some such refutations, preferably good ones?

        Given your subsequent paragraphs in the comment, it's clear you misread or misunderstood either my argument or how Aristotelian argument like Thomas' work.

        You're simply playing word games, subbing the name "Santa Claus" for the name "God." Yet this does nothing to refute Aquinas' argument or the conclusions that necessarily follow.

        It highlights one way in which Thomas' argument as he presented it in the Summa (see Andrej's comments in this thread) knowingly made a logical error. The argument imports the hidden inferences about the label "God" without justification. The only reason that the argument using "God" felt sound in the first place is that it appears to support a conclusion the theist reader already believed, in a similar way to how people commonly think "Fish live in the ocean. Whales are fish. Therefore whales live in the ocean." is a sound argument merely because it sounds like logic and they agree with the conclusion. The hidden inferences are just let slide by unnoticed. But if we decide to tack on a different name, such as "Santa Claus", where Thomas tacked on "God", then the hidden inferences become conspicuous and jarring to everyone.

        One of two scenarios are possible:

        This a fallacy known as a false dichotomy. As it happens, the truth is quite different than either option you presented:

        First, you're attempting to argue that the cosmological arguments can plausibly lead to Santa Clause as the first cause of the universe, if Santa Clause is understood as we traditionally have

        Second, ... by "Santa Clause" you're referring to a cause of the universe that is identical in every way to God except you're calling him by a different name

        Third, accurately, and again for clarity, I pointed out that one of the multiple ways in which Thomas' argument in the Summa is an unsound argument using invalid logical moves is the false equivalence made by naming the argument's conclusion "God", with all of that term's baggage, when only "first mover" could have been a valid deduction were the argument otherwise correct.

        The cause of the universe--by which we mean all space, time, energy, and matter--must transcend the universe. It must necessarily be spaceless, timeless, and immaterial.

        Why? Insofar as we know what "universe" means, we don't know any of that to be true; those are exactly the sort of things that would need to be demonstrated. One of the more flamboyant logical possibilities is the simulation hypothesis, in which the origin of the universe is neither spaceless, timeless, nor immaterial. And that's of course ignoring the fact we don't know whether the universe had a cause.

        This, of course, is not true for God, who as the spaceless, timeless, immaterial ground of being is self-existent and therefore non-contingent.

        Why? Insofar as we know what any of those terms mean, we don't know that they are properties possessed by any entity, let alone shared by a single unique entity. If you want people to believe it, there need to be reasons proportional to the claims.

        Hopefully this will definitively end the "but the cause could have been Sant Claus" reply.

        You simply repeated the same error and offered no justification for it.

      • It might be more helpful to illuminate the problem directly, rather than by argument. Let's take Thomas's conclusion:

        "Therefore it is necessary to arrive at a first mover, put in motion by no other; and this everyone understands to be God."

        Now let's taboo the term "God", substitute what that term means to the people making the argument, and see how the equivalent result holds up.

        "Therefore it is necessary to arrive at a first mover, put in motion by no other; and this everyone understands to be infinite perfection, goodness, unity, simplicity, personality, eternity, ubiquity, immutability, omniscience, omnipotence, and freedom".

        A whole lot of things appeared in the conclusion that weren't in the premises.

        • Andrej Tokarčík

          Hello, Noah. I'd highlight the structure of the sentence that You quote, namely its two parts visibly and logically divided by the semicolon.

          The first part reads "Therefore it is necessary to arrive at a first mover, put in motion by no other" It follows validly by the means of application of inference rules to the premises of the argument. It is the formal conclusion of the argument, it says that the argument standing alone shows the existence of a being that is in act without being actualised (that being is usually referred to as pure act or unmoved mover). I believe You don't have any problem so far.

          The other part of the conclusion reads "and this everyone understands to be God". Whoa, whoa, what's going on here? Of course, the argument is interesting, but it cannot be that good to prove the existence of God just like that, can it? ;)

          Well, of course it cannot, and I hope that nobody wouldn't even claim that the argument on its own fully proves the existence of God. But notice Thomas's exact wording: "and this everyone understands to be God" (emphasis mine). It should be obvious that this part of the conclusion follows only informally from the argument, since there is a clear difference in how the whole argument is performed by the means of a strict succession of logical steps mostly dealing with precise and well-defined terms, on the one hand, and how suddenly a colloquial and vague collocation of "everyone understands" is employed. That is surely eye-catching, and should be dealt adequately.

          To explain why Thomas would append such a far-stretching, even obscure note one has to consider the three factors:

          1. Building upon my other remarks, Thomas hints at the typical idea of God, which includes His being the principle of all change in the world. If God exists, He must be the being established by the First Way, for God must be pure act. Suppose to the contrary, let G be supposed to be God so that G is not pure act: then G's own potencies must be actualised by something else, denoted by X, which in turn implies that X would in this sense become more fundamental than G, which is contrary to the idea that God is the principle of all change in the world, and thus G couldn't have been God in the first place; such a contradiction is obtained whenever a non-pure-act God is assumed. All in all, everyone understands pure act of the First Way to be God inasmuch as God is supposed to be the source of all change (existence included).

          2. Thomas's target group were (beginner) theologians, neither non-believers nor apologists. As such, he could have relied upon some familiarity with how it can be known that pure act is necessarily divine, and so write "everyone understands [pure act] to be God".

          3. And finally, as I said before, Thomas did attempt to justify the divinity of pure act, later in the Summa and elsewhere. Recall how the article below which we're discussing ends, especially see the red rectangle with the quote from Feser's Aquinas.

          When one sees -- in the light of the three points raised above -- that the second part of Thomas's conclusive sentence ought to be taken informally rather than directly to follow from the argument itself, I believe that the whole thing stops seeming as far-stretched and objectionable as it initially might.

          Cheers,
          Andrej

          • "When one sees ... that the second part of Thomas's conclusive sentence ought to be taken informally rather than directly to follow from the argument itself, I believe that the whole thing stops seeming as far-stretched and objectionable as it initially might."

            I nearly agree with you. I'd say, instead, that "...the whole thing before the informal conclusion stops seeming as far-stretched and objectionable..." If more theists were serious about making a valid argument about God's existence, then they would know and make clear what is formally part of the argument and what is an informal addition to help clarify the argument for other believers. The First Way is not an argument for God's existence; it is an argument for a First Mover's existence.

            And if they were even more serious, they would quit pretending that Thomas' argument by itself proves anything at all, since so many flaws have been pointed out. Charitably speaking, a more developed version of it is needed for modern audiences, where it is supplemented by additional premises ruling out the alternatives that modern audiences are so quick to point out. Until then it is entirely unworthy of belief.

          • Andrej Tokarčík

            I'd say that Aquinas was in a good position to write the First Way (or rather, the summary thereof) in the manner he did, including the informal conclusion.

            The First Way is not an argument for God's existence; it is an argument for a First Mover's existence.

            Just a quick note: operating within the overall framework of Thomism, it is quite straightforward to deduce the other divine attributes. Thus, the First Way is only the first stage of the "proving process" inasmuch as it is studied by people who are not familiar with metaphysics in general or with the Thomistic system of thought in particular. For someone well-versed in both, the First Way is the final destination (successful or unsuccessful), as David Oderberg writes in his article Whatever is Changing is Being Changed by Something Else": A Reappraisal of Premise One of the First Way:

            "Moreover, the argument is supposed to be complete in itself, that is, to show the existence of an immovable first mover (changer) from which the other key properties of God, such as necessity and eternity, are inferred either directly or via supplementation by standard premises from natural theology. Again, this is evident from the Compendium.

            Hence the argument stands or falls on its own merits, and should not be taken as a jumping-off point for Aquinas’s other arguments, a ‘good enough’ place to start if one wants to prove that God exists, an incomplete first attempt, or some such. Either the First Way is itself a proof of the existence of God or it is not." (with a reference to the chapters 4-10 of Compendium Theologiae)

            And if they were even more serious, they would quit pretending that Thomas' argument by itself proves anything at all, since so many flaws have been pointed out.

            Most of the "flaws" are rather general questions about the framework itself and not directly pertaining to Thomas's Ways. The fact that the framework's concepts must be explained cannot be taken badly, though -- no one would expect to grasp quantum mechanics without knowledge of Hilbert spaces either.

            Charitably speaking, a more developed version of it is needed for modern audiences, where it is supplemented by additional premises ruling out the alternatives that modern audiences are so quick to point out.

            As I said elsewhere, the problem is not that there are no modern expositions of Aquinas's arguments -- there are: Feser's Aquinas mentioned in the original article is one good example. Instead, there is a popular tendency to read Aquinas as though his arguments were easily accessible without any introduction to their context whatsoever. Most infamously, it can be seen on Dawkins's attempts to debunk Aquinas's Ways in his The God Delusion, where Aquinas is once interpreted as arguing for a beginning of the universe in time, while he never meant to do such a thing. It seems to me that lack of modern commentaries is a fictitious problem.

  • Peter

    An infinite regression of causes is an impossibility in its own right. Let's assume the notion, for example, that humanity has existed forever. There would be an infinite number of generations between ourselves and an infinitely distant ancestor. However, being infinite, that number of generations could never be traversed to reach the present generation. Therefore the present generation, ourselves, could not exist. For us to exist as the present generation, there must be an absolute first generation which would render the number of intervening generations finite and therefore traversable.
    Let's substitute an infinite number of generations for an infinite number of preceding causes. By the same reasoning, an infinite number of preceding causes cannot exist otherwise we would not be here. There must be an absolute first cause which would render the intervening causes finite and traversable, ending up with ourselves in the present time.

    • Michael Murray

      There would be an infinite number of generations between ourselves and an infinitely distant ancestor.

      "infinitely distant ancestor" makes no sense. There are infinitely many negative numbers but any to of them are only a finite number apart. There is no number called "minus infinity" amongst the negative numbers.

      • Peter

        We're not talking about mathematical abstractions but about real causes. causes which create the reality we observe at the present time. It is logically impossible for dominoes to have toppled for all eternity because an infinite number of topples would have had to occur before the topple we observe at present. If each domino has to be toppled by the preceding domino, we could never reach the principal domino and so the toppling sequence could never have occurred in the first place.

        There is no difference between sequential actions like dominoes and what we intuitively observe as simultaneous actions like striking a golf ball. While our senses can perceive the fractions of seconds involved in each toppling domino, they cannot perceive the nanoseconds involved both in the electrical impulse flowing from our brain to our arm muscles instructing them to swing the club, and in the transfer of energy from the head of the club to the golf ball.

        St Thomas Aquinas was unaware of the limiting constant in nature which is the speed of light. Yet the speed of light is finite and needs time, whether we can perceive it or not.

        • Michael Murray

          We're not talking about mathematical abstractions but about real causes. causes which create the reality we observe at the present time.

          You said "logical impossibility" not "physical impossibility".

          It is logically impossible for dominoes to have toppled for all eternity because an infinite number of topples would have had to occur before the topple we observe at present.

          Oops you've done it again. You need to make up your mind if you think an infinite number of dominoes is a logical impossibility or a physical impossibility. If you think it is a logical impossibility you have to prove that.

          The simple fact is Aquinas didn't understand what we know understand about the concept infinity.

          By the way you never did tell me what an "infinitely distant ancestor" was.

          • David Nickol

            The simple fact is Aquinas didn't understand what we know understand about the concept infinity.

            It seems to me that Aquinas didn't know what we know about infinity, motion, time, and causality, and these seem all to be critically important to his arguments. Of course, I don't suppose we understand infinity, motion, time, and causality, but it seems to me we have to approach Aquinas's arguments with considerably less confidence in them he must have had and people in general who coped with them prior to the 20th century must have had.

          • Michael Murray

            Here is a quote I found on the internet from Aquinas about infinite sets:

            2 “The existence of an actual infinite multitude is impossible. For any set of things one considers must be a specific set. And sets of things are specified by the number of things in them. Now no number is infinite, for number results from counting through a set of units. So no set of things can actually be inherently unlimited, nor can it happen to be unlimited.” (Thomas Aquinas, Summa Theologica, Part 1, Question 7, Article 4).

            Of course it could be out of context but it seems clear. He's basically arguing that the only sets that exist are finite sets because you can count the things in any set. To understand infinite sets properly I guess you have to wait for Cantor in the 19th century so it is no surprise that Aquinas didn't appreciate the subtleties. I just don't understand though why, besides historical interest, anyone would want to restrict themselves to a 13th century understanding of mathematics and physics.

          • "I just don't understand though why, besides historical interest, anyone would want to restrict themselves to a 13th century understanding of mathematics and physics."

            Thanks for the comment, Michael. A few things in reply:

            First, this is what C.S. Lewis christened "chronological snobbery." It refers to an unfounded love for modern ideas, favoring newer positions over an old ones solely because of their novelty. However, what good reason do we have for believing that newer ideas are necessarily more true than older ones?

            Second, I don't know of anyone embracing an Aristotelian-Thomistic metaphysic *simply* because "they want to restrict themselves to a 13th century understanding of mathematics and physics." They hold the view because they think it is true and has since been unrefuted, not merely because it's old.

            Finally, questions about the plausibility of an infinite sequence do not even fall within the realm of mathematics or physics proper. They're questions involving the philosopher of mathematics. Therefore, advances in physics or mathematics, qua mathematics, have little relevance to the plausibility of an infinite sequence.

          • Michael Murray

            Thanks Brandon,

            It refers to an unfounded love for modern ideas, favoring newer positions over an old ones solely because of their novelty. However, what good reason do we have for believing that newer ideas are necessarily more true than older ones?

            I disagree completely that it is chronological snobbery to think that we know more now about mathematics and physics now than we did in the 13th Century. That's just a fact. Nobody favours quantum mechanics or relativity because it is novel. We favour it because it better satisfies the facts and makes better predictions. Nobody favours the rigorous definition of calculus that Newton didn't know because it is novel we favour it because it means we can understand things Newton was confused about and prove things Newton couldn't. We know these are better ideas because we can test them.

            As an example I gave a quote of Aquinas about the non-existence of infinite sets in another post. It's clear he didn't know how to approach the theory of sets and infinite sets in particular as we do post Cantor. It's not a criticism. It would have been remarkable if he had got to these ideas 600 years before Canto.

            Finally, questions about the plausibility of an infinite sequence do not even fall within the realm of mathematics or physics proper. They're questions involving the philosopher of mathematics.

            No the ability to define an infinite sequence is a mathematical result not a problem in the philosophy of mathematics. I'd also note the discussion with Peter wasn't about "plausibility" but "logical impossibility".

            Michael

          • "I disagree completely that it is chronological snobbery to think that we know more now about mathematics and physics now than we did in the 13th Century."

            Which of course is not at all what I said. I never disagreed that 1) we have made advances in mathematics and physics or 2) that embracing such advances makes one guilty of chronological snobbery.

            Instead, what I asserted is that 1) the question of whether actually infinite regresses are possible is a philosophical question, and therefore independent of mathematical or physical advances and 2) that it's chronolocial snobbery to embrace new ideas simply because they are new. This appeared to me what you insinuated when you said:

            "I just don't understand though why, besides historical interest, anyone would want to restrict themselves to a 13th century understanding of mathematics and physics."

            This seems to imply that 13th century ideas should be rejected as intellectually-restrictive simply because they originated in the thirteenth century. Perhaps I've misunderstood your statement, but if I interpreted it correctly as above, it's a textbook case of chronological snobbery.

            You can't just dismiss an idea because of its date of origin; you must engage it on its merits.

            "We know these are better ideas because we can test them."

            I of course agree that we embrace many modern theories in the natural sciences because they better fit the data than older ones. But, once more, this is not what I doubted. I doubted, simply, that philosophical claims cannot be accepted or rejected merely because of their date of origin.

            I should also note that the question of whether actually infinite regresses are possible is not a testable question. This again affirms that it's a philosophical issue, not a question pertaining to physics.

            "I'd also note the discussion with Peter wasn't about "plausibility" but "logical impossibility"."

            This affirms my original point. Logic is a philosophical discipline, not a mathematical one. Therefore, advances in the latter are independent of advances in the former.

          • Michael Murray

            "I just don't understand though why, besides historical interest, anyone would want to restrict themselves to a 13th century understanding of mathematics and physics."

            This seems to imply that 13th century ideas should be rejected as intellectually-restrictive simply because they originated in the thirteenth century.

            Surely "restrict" implies that I regard the 13th century as knowing less and that the person is restricting themselves to a smaller set of knowledge. Oh well we are clear on that now.

            We will just have to disagree on what field of study the logic of infinite sequences belongs to. Me I would put it in set theory and hence

            http://en.wikipedia.org/wiki/Mathematical_logic

          • David Nickol

            Do people here know that 1 + 2 + 3 + 4 + 5 + . . . . continued to infinity equals -1/12 (that is "minus one twelfth")? It is apparently true (in some sense, at least), although there are people who claim to be debunking it.

          • Peter

            An infinitely distant ancestor is the same as an infinitely distant domino in a supposed infinite sequence of toppling dominoes. If each domino has to be toppled by the preceding domino, one can never reach the infinitely distant domino which is necessary to topple if all the subsequent ones are to, and so the toppling sequence could never have occurred.

          • Michael Murray

            There isn't an infinitely distance ancestor or domino. Here is the model. Take the integers which are the set of all positive an negative whole numbers -55, 43, 79, -1001, 0, 3, etc. For any integer k there is a unique integer coming after it k+1 and a unique integer coming before it k-1. For each integer k take a domino d_k whose falling causes the domino d_{k+1} to fall. Ignore the physics because we are just worrying about the logic. So every domino d_k has a domino d_{k-1} that will cause it to fall and a domino d_{k+1} that it will cause to fall.

            What number is attached to the infinitely distant domino ?

          • Peter

            If you separate logic from reality, as you seem insistent on doing, you end up with absurdity or, more precisely, conclusions divorced from reality.

            In reality there can be no infinite sequence of preceding causes because such a sequence would take infinite time to play itself out. Yet that sequence terminates in the present, casting a finite limit on the time in which that sequence has played itself out.

            Another way of looking at it is that the time up to the present during which the sequence played itself out cannot be infinite because the sequence will continue into the future. The time in which a sequence plays itself out cannot be infinite in the present if it lacks the future time which has yet to be played out.

            Whichever way you look at it, a never-ending chain of causes is impossible in reality.

          • Michael Murray

            If you separate logic from reality, as you seem insistent on doing, you end up with absurdity or, more precisely, conclusions divorced from reality.

            Yes logic is divorced from reality. That doesn't make it absurd it makes it non-physical. Well I hope so because I've spent a lifetime doing mostly non-physical mathematics.

            In reality there can be no infinite sequence of preceding causes because such a sequence would take infinite time to play itself out.

            Actually this is wrong as well. Let the kth event occur at time 2^{k}. Then the events occur at times

            1/16, 1/8, 1/4, 1/2, 1, 2, 4, 8, 16, ...

            So they all occur after time 0.

            Yet that sequence terminates in the present, casting a finite limit on the time in which that sequence has played itself out.

            I've no idea what you mean by "casting a finite limit". I've given you two examples. One without mentioning time. One where the time in the past is bounded. What is wrong with these ?

            Whichever way you look at it, a never-ending chain of causes is impossible in reality.

            See my example above.

          • Peter

            Philosophy is an attempt to make sense of reality. If you admit that your form of mathematical logic is divorced from reality then perhaps you're on the wrong website. Indeed, you can even prove that 2 plus 2 equals five but that is of no use in the real world.

            The q

          • Michael Murray

            "Logical impossibility". They were the words you used. Nothing about reality in there.

            I would say that philosophy is about understanding ideas. Science is about understanding reality.

          • Peter

            Indeed, the best analogy I can think of to demonstrate the impossibility of an infinite sequence of causes is a scientific one, namely the expanding universe.

            Due to the expansion of space, galaxies at the edge of the universe are receding from us at a velocity greater than the speed of light. Consequently the light from them will never reach us and we will never see them.

            The principle is broadly the same with an infinite series of causes. As the backward series stretches to infinity, the forward series can never reach us because it has a correspondingly infinitely stretching distance to cover.

            While philosophy may be the study of the fundamental nature of reality, science does indeed assist us in understanding it.

          • David Nickol

            It seems to me that atheists don't need to worry about infinite sequences, since it seems to be the case that the universe (and time along with it—maybe!) came into existence 13.8 billion years ago, quite possibly from a timeless quantum void. The proofs of the existence of God, insofar as they involve sequences in time, can't be fully evaluated until we understand time (and causality, too). Apparently the Scholastics took time for granted, but we don't take it for granted today.

          • Peter

            On the contrary. A timeless quantum void seems to me to be a pretty complex thing in its own right, especially since countless universes such as ours are deemed to spontaneously spring from it. I would therefore expect that it needs just as much if not more of an explanation for its own existence than does the universe it seeks to explain.

          • David Nickol

            I would therefore expect that it needs just as much if not more of an explanation for its own existence than does the universe it seeks to explain.

            And yet the theist claim is that the creator of the universe is God, who is simplicity itself, and whose existence needs no explanation. What if the quantum void is a kind of equivalent to an unmoved mover or a first cause?

            In any case were are talking about infinite regression. The kind of infinite regression I am considering requires sequences in time. If there is a quantum void that is outside of time, it cannot be argued that it can't exist because there had to be something that preceded it that caused it.

            The argument seems to be that anything non-theists come up with must have a prior explanation. But theists don't explain God. So they always think they are winning the argument. But of course there are problems with the idea of God.

            Not everything in science is going to have an explanation. I have recently made reference to the concept of cognitive closure. It may be that human minds have limitations that prevent the discovery (by humans) of answers to various questions. This does not mean that the answers to those questions then must be, "Well, this is how God wanted it to be."

          • Peter

            A quantum void must be some form of quantum energy field whose fluctuations give rise to multiple universes. Therefore it cannot be nothing. It must be something quite awesome if it contains within it the potential to spontaneously create multiple space-times and multiple sets of laws.

            Being an energy field, the quantum void must be something material, and must be highly complex to possess the capability to produce multiple universes. It would require an even greater explanation for its own existence than do the universes it seeks to explain, irrespective of whether we as humans are able to comprehend it.

            That is why any material explanation for the existence of our universe, quantum void or other, is doomed to failure. Each successive background scenario is progressively more complex and requires an even greater explanation in its own right. The only rational explanation for our universe is not a material one but an immaterial one.

            An immaterial cause requires no explanation for its physical complexity because it has none. Consequently it is the only explanation our universe can possibly have without falling into the upward complexity spiral. That immaterial cause we call God.

          • Sample1

            I am not a physicist but it follows from my understanding that "timeless quantum void" is a placeholder term. I am unable to say anything more about "timeless quantum void" and I don't think physicists can either.

            May I ask what reasons are in your possession (and not in mine) for you to say "it seems to be a complex thing"?

            Thank you,
            Mike

          • Peter

            Nor am I a physicist, but I would image a timeless quantum void to be some form of quantum energy field from whose fluctuations emerge multiple universes each with their own particular sets of physical laws.

            If a scenario of countless universes with countless physical laws is required to explain the existence of our own universe, it would appear to me to be defeating the object since such a scenario would be far more complex than our universe and require a far greater explanation in its own right.

          • Michael Murray

            You are still talking about scientific things. You haven't demonstrated why the idea of an infinite regress is logically impossible, as you claimed, or what an infinitely distant ancestor or domino is. I've given you a model that works logically. I think I will stop at this point. Thanks for the discussion.

    • Michael Murray

      Or if you don't believe me

      Aquinas believed that sequential causes in the past, like a set of dominoes, could have occurred for all eternity.4

    • Why is an infinite set of causes less likely than an uncaused cause? Every cause I have ever observed or can conceive has a material cause.

      • Peter

        Does the universe have a material cause? If so, it would require an even greater explanation in its own right than would the universe it is meant to explain.

        • I do not know. I've no experience of anything causing a universe.

  • Mike

    This may sound like heresy to some, but when I was studying Aquinas in college I never found his "proofs for God" compelling. I seemed to think that if one was a Catholic they made sense, but if one of my classmates wasn't a Catholic they would respond with an emphatic "no, it doesn't have to be true" and the conversation never seemed to go anywhere.

    Even as a Catholic, I've never understood the obsession with Aquinas. Perhaps I haven't read him closely enough, but most of the time I find that his theology doesn't appeal to non-believers (or myself even though I'm a believer), and I'm not sure it advances the conversation between Catholics and non-Catholics.

    • Mike, when you studied Aquinas in college, what books or texts did you read?

      • Mike

        To be honest I don't remember. The course wasn't devoted to Aquinas. I think we had a textbook with only a chapter or two devoted to him, so it wasn't a direct text from him.

        • Thanks for the reply. I know you just said you didn't find Aquinas' proofs compelling, and not that they were false, but I'm not sure reading a chapter or two of secondary literature on Aquinas adequately or fairly presents such arguments. If you're truly interested in gauging the strengths of his arguments, I suggest one of Dr. Edward Feser's two books, Aquinas or The Last Superstition.

          • Mike

            Hi Brandon,

            You're probably right that only the cursory reading I have done isn't sufficient to really evaluate them. I spent several years in Chicago for my Ph.D. and the head of the religious studies department at DePaul University (who used to say mass at my parish) and I became good friends. We would discuss one theological principle or another and he tried to explain Aquinas to me. It just never stuck. I've read Origen, and St. Augustine, and they were ok, but Aquinas seemed distant and too dense for me.

            I've been known to have a terrible attention span for things I don't find compelling quickly, so that's probably part of it as well. Thanks for the book recommendation, if I ever see the time and energy to read up on Aquinas I'll be sure to check it out.

  • Kerk

    While I'm aware of the distinction of simultaneous and sequential causes, I don't think that even a sequential infinite regress is possible. And here's why:

    1. Every cause in the chain of infinite causes is derivative, that is, it influences the following one and is influenced by the preceding one.
    2. Impulse of movement can occur only in an independent cause, while a derivative cause can only pass that impulse onto others.
    3. Since, not a single cause in the infinite chain of causes is independent, there could not have occurred any impulse of movement.
    4. Therefore, there can be no movement in such a chain.
    5. Therefore, the chain itself is impossible.

    So, even if it's a falling domino, there can be no impulse of movement within this wholly derivative chain, unless it was imposed on it by something outside. Now the only way out is to argue that impulse of movement somehow just exists in that chain. That it's just a brute fact. But that is simply counter-intuitive and unintelligible. I mean, one could bite the bullet and keep on insisting on that, I suppose. But then I'd like to see a simple example of a wholly derivative chain that just somehow happened to move itself.

    • David Nickol

      I think the only way to settle this with any degree of certainty is to set up an infinitely long line of infinitely many dominoes and see what happens. It appears, however, that space itself is not infinite. Consequently, well before an infinite number of dominoes had been assembled in finite space, the accumulated mass of dominoes would collapse into a black hole.

      It appears that every galaxy has at its center a black hole. Since it is impossible for any information to be obtained from within the event horizon of a black hole, it cannot be proven that the black holes at the centers of galaxies were formed from huge collections of dominoes, but it is certainly not an unreasonable assumption.

      • Kerk

        What the opponent will say, though, is that the Universe is eternal or cyclical and such. It just changes on its own endlessly in time. And this is why I think it's important to show that no infinite regress in nature is possible in principle.

        Another interesting piece of information is David Hilbert's mathematical proof.

        http://www.math.dartmouth.edu/~matc/Readers/HowManyAngels/Philosophy/Philosophy.html

        • Peter Piper

          The paper by Hilbert is interesting, but it contains no mathematical proof of anything, so I'm not sure what you mean here.

          • Kerk

            Lol, yeah, I see a proof with a bunch of numbers in it and call it a "mathematical" proof. Sorry.

          • Peter Piper

            I didn't find any proofs, mathematical or otherwise, in the paper. What do you think Hilbert proved, and in which specific part of the paper do you think he proved it?

          • Kerk

            I'm not sure whether you're trolling me or not. I'm supposed to outline the paper for you? The whole point of the paper is that infinity is nowhere to be found in the material world, and it should not be found because algebraic models can measure the world without appealing to it just fine.

          • Peter Piper

            No, I'm not trolling you and there is no need to outline the paper. I don't think Hilbert proves that infinity is nowhere to be found in the material world. If you think he does, please say where in the paper he does it. You don't have to be too detailed, as long as I can find the right bit from your directions. For example, something like `in the few paragraphs just after he introduces Cantor's transfinite numbers' would be fine. If you want to be more specific, you can quote the first few words of the first paragraph of the proof.

          • Kerk

            "In summary, let us return to our main theme and draw some conclusions from all our thinking about the infinite. Our principal result is that the infinite is nowhere to be found in reality. It neither exists in nature nor provides a legitimate basis for rational thought — a remarkable harmony between being and thought. In contrast to the earlier efforts of Frege and Dedekind, we are convinced that certain intuitive concepts and insights are necessary conditions of scientific knowledge, and logic alone is not sufficient. Operating with the infinite can be made certain only by the finitary.

            The role that remains for the infinite to play is solely that of an idea — if one means by an idea, in Kant's terminology, a concept of reason which transcends all experience and which completes the concrete as a totality — that of an idea which we may unhesitatingly trust within the framework erected by our theory."

          • Peter Piper

            That is a statement of conclusions, not a proof. I don't think Hilbert provided a proof for the statement `the infinite is nowhere to be found in reality'. If you think he did, then please point out where he did it.

          • Kerk

            Ok. Then this.
            "Euclidean geometry necessarily leads to the postulate that space is infinite. Although euclidean geometry is indeed a consistent conceptual system, it does not thereby follow that euclidean geometry actually holds in reality. Whether or not real space is euclidean can be determined only through observation and experiment. The attempt to prove the infinity of space by pure speculation contains gross errors. From the fact that outside a certain portion of space there is always more space, it follows only that space is unbounded, not that it is infinite. Unboundedness and finiteness are compatible. In so-called elliptical geometry, mathematical investigation furnishes the natural model of a finite universe. Today the abandonment of euclidean geometry is no longer merely a mathematical or philosophical speculation but is suggested by considerations which originally had nothing to do with the question of the finiteness of the universe. Einstein has shown that euclidean geometry must be abandoned. On the basis of his gravitational theory, he deals with cosmological questions and shows that a finite universe is possible. Moreover, all the results of astronomy are perfectly compatible with the postulate that the universe is elliptical."

          • Peter Piper

            That is a refutation of an argument that the universe must necessarily be infinite in spatial extent. But the conclusion of such a refutation can be no stronger than `a finite universe is possible', which is in fact the conclusion Hilbert draws.

            So this is not a proof of the claim `the infinite is nowhere to be found in reality'. It could, at best, clear the way for such a proof.

          • Kerk

            It is not a logical proof beyond reasonable doubt, but it is an empirical proof, no? He effectively says, that according to our best scientific knowledge, infinity is nowhere to be found, and we don't need it to account for reality anyway. Is that not a good empirical argument?

          • Peter Piper

            No, he says that the best scientific knowledge of his time does not resolve the question of whether the universe has infinite spatial extent. This is lacking in two ways: first, saying that current scientific knowledge does not resolve the question is not the same as saying that the universe doesn't have infinite spatial extent, or even that it will not later be found to have infinite spatial extent. Another issue germane to the discussion in this thread is that the universe could have infinite spatial extent without us ever finding this out. As far as I know, this question remains open in current physics.

            Second, there are many ways the infinite could be found in reality other than by space having infinite extent.

          • Kerk

            We are going to have to agree to disagree. I read "Infinity is nowhere to be found" literally.

          • Peter Piper

            Me too. But I don't think Hilbert proved it, even in a weak empirical sense.

          • Peter

            I think we can be reasonably certain that the universe does not have infinite spatial extent. If the universe had a beginning in time and if it has expanded from that point over time, then the universe's spatial extent is limited to its rate of expansion. In other words, the space-time of our universe cannot be finite in its time dimension and infinite in its spatial dimensions. They musty both be one or the other.

          • Michael Murray

            From wikipedia:

            If, on the other hand, the universe were not curved like a sphere but had a flat topology, it could be both unbounded and infinite. The curvature of the universe can be measured through multipole moments in the spectrum of the cosmic background radiation. As to date, analysis of the radiation patterns recorded by the WMAP spacecraft hints that the universe has a flat topology. This would be consistent with an infinite physical universe. The Planck spacecraft launched in 2009 is expected to record the cosmic background radiation with 10 times higher precision, and will give more insight into the question of whether the universe is infinite or not.

            See also

            http://www.astro.ucla.edu/~wright/infpoint.html

          • Peter

            Planck's findings have so far indeed reinforced the hypothesis that the universe is flat in line with inflationary theory. However, the notion that a flat universe is infinite in extent is pure speculation for which there is no evidence. All it shows is that the universe can expand infinitely over time, which is not the same thing.

            And Planck's more finely tuned observation that the universe has a beginning in time 80-100 million years earlier than previously thought, means the universe has expanded more slowly than believed, making it even less likely that it has reached an infinite extent.

          • Peter Piper

            As far as I know, there are cosmological models consistent with our observations in which the universe has only existed for a finite time but has had infinite spatial extent ever since the Big Bang. See the link in Michael Murray's comment for more details.

          • Peter

            if you are referring to eternal inflation, then the space-time bubble which is our own universe is finite within an infinite sea of inflation-driven space-time bubbles. If you are no, please elucidate.

          • Peter Piper

            Nope, not referring to eternal inflation. It takes a while to explain the concepts involved, so I'll have to refer you to this wikipedia article, especially the subsection `Topology of expanding space'. The following paragraph from the end of the subsection summarises the key points, but I recommend looking at the rest of the article to get some sense of how the words are being used:

            Even if the overall spatial extent is infinite and thus the universe can't get any "larger", we still say that space is expanding because, locally, the characteristic distance between objects is increasing. As an infinite space grows, it remains infinite.

          • Michael Murray

            Yes that's my understanding as well. You can imagine a space-time in which the space slices are always infinite for t >0 but on which the distance between things is increasing as t increases. I think that is what they are talking about. So there is no growth from finite to infinite in a finite amount of time. Of course that means t = 0 is weird but we know the model breaks down then anyway.

          • Peter

            If you cannot explain it in your own words, then perhaps you too can't readily grasp the concepts.

          • Andrej Tokarčík

            Infinity is infinity. If something else can be added to it, then it
            is lacking in something, namely that which can be added to it, and is
            therefore not infinite in the first place.

            Is this to imply that the set of natural numbers cannot be infinite because I can add -1 to it? :)

          • Peter

            If a set of numbers were truly infinite there would exist no number outside of that set capable of being added or deducted from it. If such a number did exist outside of that set, then it could not have been an infinite set of numbers in the first place.

          • Michael Murray

            If a set of numbers were truly infinite there would exist no number outside of that set capable of being added or deducted from it.

            That is not the mathematical meaning of infinite. It doesn't mean not lacking in anything.

            In mathematics the definition of an infinite set is a set which is not finite. The definition of an infinite space depends a bit on what kind of space. Usually it means there is some way of measuring the size of the subsets of that space and also of the whole space and the size of the whole space is not finite.

            Meanwhile the last sentence makes no sense: "as infinite space grows, it remains infinite".

            The sentence is fine for a mathematician or mathematical physicist. It means that the space is already of infinite size but the way you measure size (using the space-time metric) is changing with time so that things move further apart.

          • Peter

            Just because the observable universe appears flat does not mean that the entire universe is flat. In fact the flatness of the observable universe is not quite perfect. Even if it is out by a trillionth of a degree, it could mean that space on the scale of the entire universe is spherical and therefore finite, although still unbounded. In this case, no matter how much space expanded between two objects, it would always remain finite.

            I'm not saying it's you, but atheists will try to use the apparent infinity of the universe as an argument against God, especially since the Catechism says that God is infinitely greater than all his works (CCC300). How could God be greater than an infinite universe? Either the universe is finite or the Catechism is wrong.

          • Michael Murray

            Just because the observable universe appears flat does not mean that the entire universe is flat.

            Of course. Neither do we have evidence that the whole universe is flat. What we do have is evidence compatible with the possibility that the universe is flat.

            How could God be greater than an infinite universe? Either the universe is finite or the Catechism is wrong.

            Just for once i don't see the problem with the Catechism. When we say the universe if infinite we are just saying something about how "big" it is. I doubt very much that the Catechism is referring to how "big" God is when it says God is infinite. I thought it meant God was "unlimited" in the sense that you can't say "God cannot do this".

          • Peter

            Even though Planck's triangulation of the hot and cold spots of the cosmic background radiation revealed a remarkable degree of flatness, it was not perfect flatness. Therefore it is premature even to suggest that the universe is flat and infinite.

          • Michael Murray

            I'm not saying that. I'm saying that so far we have nothing to show it might not be flat and infinite. Also according to wikipedia:

            The latest research shows that even the most powerful future experiments (like SKA, Planck..) will not be able to distinguish between flat, open and closed universe if the true value of cosmological curvature parameter is smaller than 10−4. If the true value of the cosmological curvature parameter is larger than 10−3 we will be able to distinguish between these three models even now.

            Personally I have no dog in this race. It is what is.

          • Peter

            My conclusion is that the flatness is so pronounced and the curvature so slight that the universe is truly vast yet spherical and finite, prevented from imploding by its dark energy expansion. Its sheer size is a testament to the power of the Creator.

            Unless presented with indisputable evidence, I cannot accept an infinite universe for, as a Catholic, I believe that God is infinitely greater than all his works. If the universe is spatially infinite, it has no bounds and contains an infinite number of things an infinite number of times. This makes a mockery of God's creation since we believe that everything was created for a purpose. There is no purpose to the same thing existing an infinite number of times.

            Furthermore, God cannot be infinitely greater than a spatially infinite universe because he cannot meaningfully add anything to something which already exists an infinite number of times. Therefore he has no control over the universe which means he is not infinitely greater.

            The only way one could rationalise an infinite universe with God would be to make the universe synonymous with God, thereby creating a pantheistic universe where God and the universe are the same thing.

          • Michael Murray

            You are deeply confused about the meaning of infinity.

          • Michael Murray

            I think there is a language conflict here. I've struck it before when people say something like "God's infinite love" they mean "God's unbounded love" or "God's unrestricted love" etc. I had a long discussion which finally wound up when I realised we where using the same word for different things. Of course in this case the context is mathematics and physics so that definition should be the one used.

          • Andrej Tokarčík

            I'd second vehemently that when discussing infinities one must stick to a very clearly specified meaning of the words involved. That's why I reacted the way I did, intended the comment to be more of a pun than a serious note, to illustrate the fact that "Infinity is infinity" might be oversimpliyfing matters :)

            Cheers,
            Andrej

          • Andrej. I couldn't reply to your post above as it is awaiting moderation. I think this dialogue is outgrowing the com-box. I will post a blog about this and we can continue there if you like briangreenadams.wordpress.com

            "But is it really so that today we're in a position to positively claim that all natural phenomena have a material cause?"

            Well there is really no need for such a claim. Mine is: as far as we can tell all causes are material in some sense.

            "But how is this not analogical to the motion of sun, which seemed to the medievals to be without a material cause?"

            This
            is exactly my point, it was wrong to assume no material cause for the
            Sun's apparent motion, we should not make the same assumption with
            respect to the appearance of virtual particles or the earliest known
            state of the Cosmos.

            "I haven't limited myself to material causes only, while You have."

            I
            have not ruled out immaterial existence, I just see not reason to
            accept it. My dispute with you is that when you do not detect a material
            cause, you conclude an immaterial cause. I would say this is
            fallacious. It is arguing from ignorance.

            "The question is: which of the two chains of reasoning we presented is more probable to be correct?"

            Based on the fact that all observed causes are material I would say it is more likely that all causes are material.

            "That's how I observe it!" is not a real justification and is prone to errors of purportedly bullet-proof induction, as I'll try to demonstrate in the next example."

            Of
            course induction is not bullet-proof, it leads to weak positions. When I
            say something is established inductively, I mean it "appears" to be the
            case. This is what inductive arguments do.

            Your example more or
            less sets out the problem of induction. We have no way of knowing that
            past patterns predict the future but we all behave as if this is the
            case. This is what I mean when I say I take the reliability of induction
            as axiomatic.

            I have read the Black Swan twice and I am almost
            done with Anti-Fragile. You should read the whole thing and I suggest
            you have a close look at chapter six which begins with "On the Causes of
            My Rejection of Causes"

          • Andrej Tokarčík

            Brian, I don't know how the moderation process work, so please write the blog post, I'd love to continue our discussion there :)

            For now, I'll just make a quick reply:

            This is exactly my point, it was wrong to assume no material cause for the Sun's apparent motion, we should not make the same assumption with respect to the appearance of virtual particles or the earliest known
            state of the Cosmos.

            The point of the analogy wasn't to suggest that the sudden appearances of particles do not have a material cause, but merely to show that inferring from our current knowledge that it doesn't have a cause at all is as illogical as it was for the medievals to think that the motion of Sun does not have a material cause.

            Cheers,
            Andrej

          • David Nickol
          • Peter Piper

            I recommend that you look at the rest of the article to get a sense of how the words are being used. Once you do this, I hope you will see that the sentence does after all make sense.

            In particular, the word `infinite' is being used in the modern mathematical sense, not in the older sense of `unlimited'. Also, `grows' is used to mean that the characteristic distance between objects increases over time (they move apart because of the expansion of the space between them).

          • Peter

            I understand that as space between two objects expands, this does not mean that space overall is expanding like a balloon into nothingness because such a concept is meaningless. Consequently there is no definable edge or boundary to space. And if space is flat and not spherical, going in one direction will not bring us back to the same place. Therefore in such space you can go on forever without either reaching the edge or returning to where you started. In that sense, then, I suppose you can call it infinite. And that does not change even as space continues to expand between two objects.

            However, even though we measure space on large scales as being flat, the scales on which we measure it are still necessarily within the confines of our observable universe. And if as we suspect, the observable universe is only a small fraction of the total universe, then space which appears flat in the observable universe may indeed be curved in the total universe, very much like a field appearing flat on earth. In that case, the universe would be spherical and therefore finite.

          • Peter Piper

            You are absolutely right. At the moment, the question of whether the universe is spatially infinite cannot be answered on the basis of the available scientific evidence.

  • HenryBowers

    I think the act-potency paradigm is difficult because it presupposes a causal rule, a "transtemporal actuality" that requires potentialities to be reduced into acts. I think the easier route is to follow Aquinas' commentary on Aristotle's Physics, and show:

    (1) If the first mover were moving by himself, nothing at rest would affect his movement.
    (2) But time and motion are divisible into parts.
    (3) Therefore, if the second half of (1)'s motion was at rest, then the first mover could not move by himself.
    (4) Therefore, the prime mover does not move.

    That proves the unmoved-ness of the Prime Mover, and weakens the locomotive analogy, IMHO. To prove the existence of a Prime Mover, Aristotle's proof is long and complex. Aquinas has a shortcut from Christianity:

    (1) If the finite duration from Creation until Now is one motion, and
    (2) If this one motion cannot be the Prime Mover (see #1-4 above)
    (3) Then a Prime Mover exists who is not this one motion.