Three things I do not understand about the argument from motion.

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Posted by Noble_monkey
5/22/2018 5:56 pm
#1

I only have three issues with Aquinas' first way that are hard to rationalize and am struggling with.

1) Why does the prime mover need to be pure act rather than a composite of act and potency? In an essentially-ordered series, the derivative instruments do not generate the causal power but merely pass along the causal power  but they must derive this motus from the prime mover. I understand that there has to be a prime mover for the effect to be there or else if there is no Prime mover, the derivative instruments would pass no causal power along and there would be no change which of course is false because we do observe change. I have trouble understanding Aquinas where he just jumps from a being that has the act to actualize these potencies to a being that is full on pure act. For example, it can be a composite of act and potency as long as its potencies are not actualized in that specific essentially ordered series. For example, we can have a laser that produces light that bounces off mirrors and so on. In that case, the laser is the prime mover and is act with respect to light but it is still a composite since it has other potencies that are not actualized within that series like catching on fire, be destroyed, changing color, etc.

2) 
Why can't the prime mover be a particle or a field. You might say that they are composites because it has potencies like coming apart and sticking together, changing location and moving through time, etc. but let's look at the series again. Let's take a look at the laser series. The field would produce the light which would be passed down the series. Since the other potencies of the field or particle is not actualized in that essentially-ordered series, why can't we pass off the particle/field as the prime mover at least for this series?

3) Would not series which are composed of both derivative instruments and nonderivative beings dissolve the need for a prime mover?


Thank you guys in advance for answering my concerns. 

I was hoping to understand this argument fully in order to defend it against atheists.

 

Last edited by Noble_monkey (5/22/2018 5:59 pm)

 
Posted by Miguel
5/22/2018 11:56 pm
#2

I think there are different ways to answer those questions, but here's what I'd say. I'm not sure if Feser would reply in the same way I do, but anyway:

1) This is a common question. We might say the First Cause is purely actual with respect to existence, but what if it has some unactualized potencies for other things (other than existence)? Well, one way to argue the First Cause is wholly actual in every aspect would be by appealing to the principle of proportionate causality: whatever perfection is in the effect must first be present in the cause. This is a very sensible principle that follows quite simply from PSR and PC (Feser defends and explains the principle of proportionate causality in the book, by the way). Basically, if there was a perfection in the effect that was not present in the cause, where would that perfection have come from then? The greater cannot come from the lesser. The cause must at least be in the same level of ontological perfection as the effect, otherwise the "extra" or "surplus" perfection would be coming from nothing.

For example: it is generally agreed in the philosophy of mind that if our thoughts really are immaterial, then they cannot be entirely produced by our brains. Because if our thoughts transcend matter, then obviously they cannot be caused by matter; there wouldn't be anything in matter that could cause something that by its very nature transcends matter. This is an instance of the principle of proportionate causality. Whatever is in the effect must first be in the cause, at least in the same level of ontological perfection.

Now consider that the First Cause, precisely because it is the cause of all beings which are a mixture of potency and act, is the cause of everything other than itself -- everything that is not pure act. Therefore the First Cause must have all positive perfections. It doesn't lack anything. It is the cause of all possible contingent things. So it has all pure perfections (otherwise some perfections in the world would be coming from absolutely nowhere). So the First Cause is purely actual; not only with respect to existence, but to every possible positive perfection out there; every perfection that is not itself the product of some intrinsic limitation.

Another way to argue this is from an analysis of Being. The First Cause is Pure Existence, but Existence or Being is the supreme perfection, etc, but that requires some analysis of the transcendentals.

2) Since I already provided an argument for the First Cause being wholly actual, I take it that this question has already been answered. However, I'll add this: We don't need to show the First Cause is wholly actual in order to refute the idea that it could be a particle or a field. It is enough that the First Cause is pure act with respect to existence, because particles or fields, like any material things, are just not purely actual when it comes to existence.

A being who is Pure Act would be a necessary being. Since it just is a pure act of existence, it could not fail to exist, not even in principle. It has necessary existence. But it is very implausible to say material things (like a particle or a field) could have necessary existence. It seems we can conceive the non-existence of any material thing. There could have been no universe, no multiverse, no physical things. In fact, many scientists believe the universe had an absolute beginning, and whether or not this is true, it seems it could at least be *possible* - hence why some scientists can even believe it to be real. But if a material thing were necessary, it couldn't even *possibly* fail to exist.

Furthermore, in A-T metaphysics material beings are hylemorphic composites of form and matter. But whatever is a composite of form and matter is not Pure Act or a necessary being; form is to matter like act is to potency; and a thing's form (essence) would be distinct from its existence (form+matter, as informed matter), so no necessary existence.

So even if the First Cause were only pure act with respect to existence, material things like particles or fields would not be plausible candidates for a purely actual being.

3) I don't quite understand the question. In the First Way we are concerned with explaining the continued existence (actuality) of changing things (mixtures of potency and act). The actual existence of a changing thing is caused by another changing thing, whose existence is then caused by another changing thing, whose existence is cause by another changing thing... And unless there is a being who just is Pure Act, and therefore has Actuality all by itself as its own nature and doesn't need to be actualized by anything else, the whole series would be entirely groundless, like an infinite series of train carts with no engine to move them. ANY being who is not Pure Act with respect to existence will always be dependent on a cause for its existence -- in other words, something that actualizes its perfection/potential for existence.

 
Posted by RomanJoe
5/23/2018 1:14 am
#3

But any composite being requires an explanation for its specific composition. If this wasn't the case then you would be admitting that there are some things that don't require an explanation--that there are some things that have no sufficient reason for their being, no intelligibility. In such a case you are really saying that PSR isn't necessary and that brute facts could exist. But if that's the case then why did you need to climb all the way back to a prime mover with pure actuality (at least in some respect) if you could have stopped at quantum particles, or atomic structure, what have you. Perhaps the explanatory buck stops at an earlier level, perhaps inquiry into the explanations of composite beings is merely a delusory practice of wishful thinking, of hoping that explanations will under-gird every inch of our universe when in reality they just happen to occur and may not occur sometimes--all without rhyme or reason.

So to return to the act-potency composition. If a being is potential in some respects and actual in others, naturally we seek an explanation for why it is divided in this way--not an explanation for why it is a composite of actual and potential existence in a general sense, but rather an explanation for why it (e.g. an ice cube) is specifically actual (solid, cold, cubic) as opposed to being actual in its current potential states (liquid, amorphous, warm), In such a case we appeal to a logically prior cause to explain the specific composition of actuality and potentiality. Why? Because there is nothing in the composite being itself which can explain its specific composition. There is nothing in mere solidity, coldness, or cubicness, that explains why it happens to be that way. There is also nothing in its potential states of liquidity, shapelessness, and warmth, that explains why it is actually and potentially the way it is. So we must look outside of the composite being to a logically prior cause in order to explain its composition. And, lest we forego the principle of causality, this cause can only actualize the ice cube's specific state of being solid, cold, and cubic, if it is actual itself. So we may appeal to the surrounding coolness of the air in the freezer alongside the ice tray which gives it its shape. Of course we can also appeal to simultaneous causes like the rigidity of its molecular structure, the atomic structure that underlies that, the subatomic, and so on and so forth. But what we're doing in each case is trying to provide a sufficient causal explanation for the specific way in which something is in actuality and potentiality. 

In short, as long as there is a being with a specific composition (be it act-potency, form-matter, essence-existence) there is some causal explanation for why it happens to be composed in the way it specifically is. So if you were to argue that the prime mover is only actual with respect to the existence of derivative beings in a causal series ordered per se. We would still need a reason why the prime mover has potential existence along with its actual existence. Now we could say that it's purely actual in one respect and potential in others because there is a logically prior cause which is actualizing its efficacy for purely actual existence while not actualizing the other potentials. But if that's the case then it would really be this logically prior cause that is the prime mover. Now if you were to answer that it's just the case that the prime mover happens to be potential in some manner and actual in others, and you haven't given a reason why, then you are again undermining PSR which is what we need in the first place to get the argument off the ground. You can go ahead and be skeptical of PSR but then your worries are not just trying to defend pure actuality, they would be trying to defend a principle of reality we all--at some level--seem to take for granted. 

This should answer question 2 for you. I'm unsure what you're trying to ask in question 3. 

Last edited by RomanJoe (5/23/2018 1:27 am)

 


 
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