Gordon Clark on Aristotle’s Theory of Motion

In Thales to Dewey, Gordon Clark provides a fairly detailed analysis of the basics of Aristotle’s system of thought.  These basics are still debated today because they don’t only apply to Aristotelianism.  Concepts such as definition, substance, unity, individuation, motion, space, time, etc. are ideas used by almost everybody.  However, they can be quite difficult to understand and the consequences of false beliefs about these issues can be far-reaching.  Moreover, one of the first things that a theology-enthusiast may notice when learning about Aristotle is that many theologians of history employed the same technical terminology as Aristotle.  Therefore, an understanding of the Aristotelian background of terms such as substance, quality, nature, person, individual, numerical unity, subsistence, essence, generation, etc, can shed light on historical theology.

Around the middle of Clark’s explosion of Aristotle’s The Physics, he begins to discuss motion.  Motion is the phenomenon that underlies all physics and all change.  The principle of motion is nature.  By nature, a stone dropped into the lake moves to the bottom and stops when it implants itself in the mud.  The selection below is from Clark’s explanation of Aristotle’s definition of motion.  All material is taken from P. 107 to 108 in Thales to Dewey.

Since nature is defined as a principle of motion, it is necessary to understand the meaning of motion in order to understand nature. Eventually Aristotle classifies change into types: generation and corruption; qualitative, or, in modern terms, chemical change; quantitative change, as growth and decay; and motion through space. All these are discussed at greater length than can be afforded here. Then, too, it is necessary to discuss continuum, infinity, place, void, and time, for these terms must be used in the explanation. But, first, motion must be defined.

Now the stage is set for a discussion of the definition of motion.

In the section on Logic the solution of the paradox of learning as presented in the Meno depended on the distinction between actual knowledge and potential knowledge. Also, in the section on the Law of Contradiction, the problem of the coexistence of contraries was solved by the same distinction. These concepts of actuality and potentiality are basic in Aristotle’s thought, and here they are necessary for the definition of motion.

Just as learning was defined in terms of actuality and potentiality, now motion will be defined in these terms.

But potentiality and actuality cannot be defined. Just as conclusions depend eventually on indemonstrable premises, so various terms are at last defined by means of indefinable concepts. The mind must grasp them intuitively from experience. That a piece of marble can become a statue and that an ignorant boy can become a learned man are matters of common experience. Again, a scholar asleep can wake up and start to study. An induction from such cases gives the concepts of potentiality and actuality. These are not to be defined, but are to be grasped by analogy. As he who can build is to him who is building, and as he who, though not blind, has his eyes shut is to him who sees, so potentiality is to actuality.

Aristotle advocates the idea that not all terms can be defined.  The most basic of terms must appeal analogically to experience.  Therefore, potentiality and actuality will not here be defined except with examples.  Note that Clark is not giving his opinion yet.  He is only expositing Aristotle.

With these indefinable concepts it is possible to define change or motion in general. The definition is: “the actualization of the potential as such is motion”; or, “the actuality of a potential being when it is actual and operative, not as itself, but as movable, is motion.”

Now that potentiality and actuality have been invoked, Aristotle defines motion as the actualization of a potential.

Aristotle elucidates with examples. When the buildable, in so far as it is buildable, is in actuality, the change called building is going on. Or, when we say that bronze is potentially a statue, it is not the actuality of bronze as bronze which is motion, but the actualization of “potentially statue,” the actualization of the bronze as changeable, which is motion.

Examples of what is and isn’t motion are provided.  Now, Clark goes on to critique Aristotle.

Now, it may be quite true, as Aristotle goes on to argue, that all previous attempts to define motion were failures. This in itself, however, does not prove that Aristotle’s attempt was a success. On the surface it seems that his definition of motion uses the very concept being defined. Motion, he said, is the actualization of an object in so far as it is movable. But if the meaning of motion has not yet been determined, the phrase “as movable” adds no information. Next, the term actualization – unless we translate it actuality – apparently refers to some sort of process and hence presupposes a definition of change.

Clark argues that since the term actualization probably refers to a process, motion is presupposed in the definition of actualization.  This would make Aristotle’s definition circular.

And, finally, not to press the problem of deriving the two terms by analogy, actuality and potentiality are hardly suitable for explanatory processes. No doubt bronze can be made into a statue – this is a matter of experience. But to explain why bronze can become a statue, the statement that bronze has such a potentiality does not increase our knowledge. To assert that a certain matter is potentially a certain form means only that similar matter in the past has become that form. This is a statement of fact; it is not an explanation of the fact.

First, I think it is important to call attention to Clark’s passing statement:  “…not to press the problem of deriving the two terms by analogy…”  Gordon Clark does not allow, here and in his other writings, that terms be allowed to be undefined.  However, he does not want to refute that point here but rather show that the potentiality-actuality explanation still doesn’t explain motion, it just tells you that it happens.  Clark concludes this section:

Perhaps Democritus was right, and there is no explanation. Motion is just an inexplicable factor of experience, and only particular motions can be defined or explained. Or, perhaps, the Eleatic arguments against motion were just so much conceptual jargon, and to refute them all that Aristotle needs is more conceptual jargon. In modern times, too, Bergson has complained that his immediate predecessors failed to explain motion.

Classical ApologeticsPresumably, Clark is referring to the 19th-20th century French philosopher Henri Bergson.  All this is quite interesting, and it underscores the importance of a continued re-examination of the basics of our thought.  If motion is just a vague term describing who-knows-what, the world may perhaps be a bit different than we’ve been told it is.

Indeed, scientists have already rejected the Newtonian principles of motion.  Perhaps it would be best for modern theologians to follow Gordon Clark’s example and construct and defend a system of theology that is not based on Aristotelian physics which has been mostly rejected by modern physicists.  This is not to say that Quantum Mechanics or General Relativity are true either.  There will probably be more successors.  Rather, I think we need a foundation for the Christian faith that is stronger than Aquinas’ Cosmological Argument (which, if you read the Summa Theologica, you will see is heavily reliant on Aristotle’s physics, so the Classical Apologists should worry about these things).   In fact, we ought to have a foundation for the Christian faith that can refute it.

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  • Ryan

    I’ve been reading Feser’s book Scholastic Metaphysics, which defends a metaphysical theory rooted in Aristotelianism. Very stimulating, I think you’d enjoy it.

    Anyway, I believe Feser would say that a potentiality is a thing as it could be, whereas an actuality is a thing as it is. Besides God, who is supposedly pure act (and this is divine simplicity), beings are a mix of actuality and potentiality. Actualities can have causal “powers” to actualize or make actual various potencies, thereby providing for the possibility of change, contrary to and providing a middle ground between Parmenideans (being is pure act = no change – and interestingly, this seems to cut against divine simplicity, for it implies that a God who is pure act would mean nothing could have ever changed) and Heracliteans (being is pure potential = only change). Insofar as it’s considered a theory of change, and abstracted from various Thomistic or Aristotelian accouterments, act/potency doesn’t look too bad to me.

    You might question the use of thing, being, existence, whatnot, but if you exchange these terms for “subject” or the like I think you can understand what he’s getting at. He cannot, at least, be blamed for a lack of trying to define relevant terms. I would say, of course, there a few holes within Feser’s own position – particularly due to his Thomistic precommitment to absolute divine simplicity, his seeming theory of time, theory of matter (I’ll be very interested to see if he gets around Clark’s critique of prime matter), and probably his view of substance, existence, and essence (have gotten to these chapters yet, but I’ve seen enough foreshadowing that there appears to be something amiss here) – but I do wonder if the act/potency model in its general construction as put above is possible to salvage. Halfway through the book, I’ll probably do a review when I’m done with it.

    Unrelated, I also wonder if the Aristotelian theory of universals (viz. they don’t “exist” apart from concretes) doesn’t make some sense in light of the fact nothing exists independently of God, yet God Himself is not a composition of prior or more fundamental parts which would have independent existence (a la the route a more Platonic view of God might have to go if one rejected divine simplicity). Depends on what is meant by “exist,” I suppose.

    • I put it on my amazon watchlist. Where did you get it? It’s expensive on Amazon.

      That is an interesting thought that “actualities can have causal ‘powers’ to actualize…various potencies.” Does that mean, though, that actualities are potentially powerful to actualize potencies? If so, is that a problem?

      I’m looking forward to reading your review. Here’s a few more thoughts on what you said:

      Moreover, if actuality is a thing as it is and potentiality is a thing as it could be, it makes sense that motion is a thing as it is becoming the thing as it could be. But now, I wonder if the difficulty has merely been shifted into the word “becoming.” Or the word “change” could be substituted for “become” but the difficulty persists.

      Yea, I’d be very interested whether or not he get’s around Clark’s critique of matter as the principle of individuation (is that what you meant by “Clark’s critique of prime matter?).

      • Ryan

        I got it as a Christmas gift. Note sure where they got it.

        “Does that mean, though, that actualities are potentially powerful to “actualize potencies? If so, is that a problem?”

        It does mean that, at least for God, but I don’t think it’s a problem. Take someone like yourself first. Feser would say you are a certain way – actual – with certain things you could do – potentialities. You are reading this, or you are entertaining some thought stimulated by this – though this is accidental to your essence as a human, and so was a some point only a potentiality also – whereas you could respond or not (assuming God could have instantiated either possibility). Both actuality and potentiality are kinds of states of being, and you have them both.

        Now, you are contingent. Your essence was at one point only in a state of potency with respect to existence, so your essence’s own actualization is due to something else which must have been actual. Eventually, there must be someone whose essence was not in a state of potency with respect to its existence, and this is God.

        Feser and his fellow Thomists are at this point, I think (but am not sure) quick to jump to the conclusion that God must be pure act. “Pure” act has several problems with it, e.g. that insofar as God’s will is essential to Him, God’s willing of creation is also essential to Him, and thus He is dependent on creation. He could not be God without there being a creation. More technically put, the Trinity aren’t sufficient within themselves. Another problem which follows from this one is that nothing could have potential, for everything would be actualized necessarily. Insofar as potential connotes contrary possibilities, there would be no potentialities. The essence of creation would never really have been in a state of potency with respect to its existence. The creator-creation distinction is blurry.

        Rather, what we can say is that God’s essence is not in potency with respect to His existence (depending on what Aristotelians/Thomists mean here). This does not imply that God has no potentiality at all. The self-knowledge and love among the members of the Trinity show the essentiality and eternal existence of their intellects and volitions, yet it does not show that every instance of intellection or volition is essential. We could say they actually have the potential to do or think x or y through their causal power, or we can say that while God must act, He needn’t act in a certain way. So an argument for simplicity or pure act must follow by other means.

        Feser argues on his blog (and he may go into this further in chapters 3-4) that any mix of actuality and potentiality implies that a being is composed of prior, fundamental parts, and God can’t be God if there is something more fundamental than He is. But at the moment, if this is all Feser has, there seems to be a very good reply: if the very Aristotelian idea of universals he espouses is true and universals can’t “exist” apart from concretes, then there isn’t any a prior reason I can see to suppose that a being can’t be a mix of both act and potential but be actual with respect to its existence. Instead, a being can’t be both actual and potential at the same time and in the same respect (pg. 128), and with this someone who rejects divine simplicity but accepts act/potential could agree. Even if the Aristotelian idea of universals isn’t true, for that matter, universals and the Trinity may be mutually dependent, and this too would suffice to counter Feser et al. who would say it’s divine simplicity or else something is more fundamental than God.

        “Or the word “change” could be substituted for “become” but the difficulty persists.”

        I’m not sure which difficulty you’re talking about, but I have noticed Feser seems to take the A-theory of time completely for granted in earlier chapters. It appears he will later talk about time, but only very briefly, much too briefly for me to think he’s covered all his bases.

        “is that what you meant by “Clark’s critique of prime matter?”

        Yes. Feser, for example, has made a few seemingly incompatible claims about “prime matter.”

        Pg. 38: “Finally, act is prior to potency insofar as while there can be nothing that is pure potency – since, if a thing were purely potential and in no way actual, it would not exist – there can be something which is pure act. The notion of that which is absolutely pure actuality of actus purus is the core of Scholastic philosophy’s conception of God, and its existence is the upshot of the key Scholastic arguments for God’s existence.”

        Pg. 40: “Where the essence of material things is concerned, we can in turn distinguish further between prime matter, which is pure potentiality for the reception of form, and second matter, which is matter which has taken on some substantial form but is in potency relative to the reception of accidental forms. (More on this in chapter 3.)”

        Pg. 126: “We might say that insofar as quantum theory point in the direction of pure potency of prime matter – in its indeterminism, in the Bell inequalities, and in the notion of particles popping into existence in a quantum vacuum – portrays the actualization of potency without portraying something doing the actualizing, it approximates the notion of potency without act.”

        Now compare this with Clark:

        Clark and His Critics, 2009, p. 410:

        //”This material on individuation, including the footnote, shows that Empiricism can produce no knowledge of individuals whatever. Neither wife, nor firend, nor the tree on the lawn can be known. Since Clark’s opponents have so emphatically asserted that they know individuals, Aristotle, their patron saint, has delivered the coup de grace. Study the footnote again. What makes an individual an individual? It is the matter on which the form is impressed. The form is the universal. As form is constitutes the species, identical in, or, as Aristotle said, common to all the members of the class. Tree have many qualities in common, but this tree is this tree, and the other is the other, because of its matter. The individual thing is the basic reality. Notice again the sentence immediately preceding the footnote, condensed: “if these primary substances did not exist, it would be impossible for anything else to exist.” But matter is pure potentiality, actually nothing, and unknowable.

        In his Thales to Dewey (143-144), a section which these apologetes overlook, Clark, expounding Aristotle, wrote, “The things of experience… are all composites of matter and form; below the simplest natural objects, the elements, themselves composed of matter and form, lies the pure matter…. An individuality that is based on matter is a negative thing.” Preceding the sentence Clark had already said “since matter is a virtual non-being and is unknowable, the primary realities, the independent and basic things of the universe are beyond understanding.//

        Guess I’ll have to wait for chapter 3 in Feser to see how or if he addresses this point.

        • The problem that I was trying to highlight is this. It seems that nothing can be both actually p and potentially p in the same sense. If actuality has potency, and if this implies that actuality is potentially potent, then even when something is actually p, there is potentiality mixed in. Then, a priori, nothing, not even pure act, is purely actual and non-potential. Doesn’t that seem difficult to swallow?

          And yea, the prime matter is the issue I was referring to. Keep me posted as to whether or not Feser addresses it.

          • Ryan

            I’m not sure I follow. “If actuality has potency…” – what does this mean? Actuality and potentiality are really distinct. Beings are both a mix of actuality and potentiality. One isn’t reducible to the other.

            I am hypothesizing that God is actual in reference to His existence/essence and must always have been so, and while He is actual in reference to His will respecting contingencies now, He needn’t have willed what He did, so He too had potential which He actualized (eternally). The actualization of His will was necessary, but what the direction of what He actualized through His will was not. Thus, God had to eternally choose to do something – e.g. create or not create – but He didn’t have to choose the one or the other.

          • I’m referring to your sentence where Feser says: “actualities can have causal ‘powers’ to actualize…various potencies.” Doesn’t that mean, though, that actualities are ‘potentially’ powerful to actualize potencies? If so, then act itself is potentially powerful. Therefore act is potential in some respect.

          • Ryan

            Potentialities limits what can be actualized, but every potentiality, if actualized, is actualized by an actuality. So every contingent actualization of a potentiality is traceable to a non-contingent actuality, God. I don’t see how this implies God is pure act nor that act is potential in some sense.

            “actualities can have causal ‘powers’ to actualize…various potencies” just means, I think – I may have misspoken, but I don’t think so – that some actualities have causal powers and some don’t, not that an actuality that has [actual] causal powers is only potentially powerful.

          • If a particular actuality has causal powers, doesn’t this mean that it can cause things to happen? If so, then it potentially causes things to happen. If so, then this particular actuality is, iteself, potentiality, which is absurd.

            For example, if my actuality wrt existence has causal powers, then my actuality wrt existence can potentially cause things.

          • Ryan

            It can, but only insofar as it is actualized by the actuality. Supposing we as Calvinists believe that God’s eternal actualization of this possible world determines what every actuality such as ourselves will actualize thereafter, we may still be said to be a mix of actuality and potentiality insofar as there are circumstances under which we would have actualized other than we have – namely, a different divine decree or actualization. Is this not an example of how an actuality which has causal powers only contingently actualizes potencies?