St. Thomas Aquinas’ First Way for the Existence of God:
- If potentialities could actualize themselves, then they already would have done so and nothing would not be changing
- Things are changing
- Therefore, potentialities cannot actualize themselves
- Therefore, there exists a First Cause
Thus concludes Aquinas’ First Way for the existence of God. This is the second part of his argument, and by far the most important part. It’s very compelling and looks valid at first glance.
Once one finally understands what is meant by potency and act, essential and contingent, and all of the other medieval terms Aristotle and Aquinas used, the argument appears inescapable. More often than not, I have personally tried to refute premise 3, and say that there exists “self-actualizing potential”.
Or, you can redefine potentiality in such a way that does not preclude this possibility. While this can be attempted empirically (such as in my previous article), as we may come to find in quantum mechanics and virtual particles, I think there’s a simpler route to take.
In fact, the detail is so small that it often goes unnoticed, passing under our metaphysically intuitive radar. I am speaking of (2), that things are changing.
Parmenides’ Bifurcation:
The premise is a reference to the philosopher Parmenides, who divided his train of thought into two categories. To him, “stuff” was either existent, or non-existent. It made no sense, then, to speak of non-existent stuff. As a direct result, Parmenides is notorious for suggesting that the world cannot change, and that it is therefore eternal. The change we see in the world is but a mere illusion, and there is indeed no such thing as change.
Many miss this point, and suggest that Parmenides was obviously wrong. After all, plants grow, flowers bloom, ice melts, rocks fall, and people move – clearly change is everywhere. The Parmenides criticism of Aquinas comes with premise 2, that things are changing. Parmenides might suggest that Aquinas equivocates on the word ‘change’ - it’s a matter of perspective. From the Universe’s perspective (or from God’s perspective, if you will) nothing ever changes.
While Parmenides himself wasn’t talking about the Law of Conservation of Energy, his ideas are what gave way to their development. He is speaking about change in a very specific manner: a transition from non-being (non-matter) to being (matter). He was not describing a change in state like solid to liquid to gas. He was not describing a change in flowers at all. This he thought to be an illusion because it is not true change.
Parmenides is discussing change from non-existence –> existence, as opposed to existence –> existence.
In discussing this with Edward Feser, who I’ll gladly grant the epithet of being perhaps the most respectable and intelligent Thomist since Aquinas, he states the following to me:
One objection I would have to what you say here is that the Aristotelian-Thomist view is not that potencies are non-existent, but that they are non-actual.
What is meant by non-existent? Clearly, any Aristotelian-Thomistic scholar would say “having full potential but no act”. But what does this mean or imply? To the Thomist: a being of pure potential can not do anything, such as actualize itself (premise 3).
Continuing with Dr. Feser’s point:
The whole point is to reject Parmenides’ bifurcation between complete being and sheer non-being — a potency is neither complete or actual on the one hand, nor non-existent on the other, but something in between.
To be, according to Aristotle, is to be something in particular. This is the essence of his Metaphysics.
Even from his logic and Law of Non-Contradiction (everything is either A or not-A), it is apparent to Parmenides that no middle ground can exist when talking about being or existence. To him, something cannot “sort of” exist. It either does, or it does not.
Dr. Feser, of course, has already anticipated this as follows:
Another problem is that precisely because they are non-actual, they can’t do anything even though they are not non-existent. Only what is actual can do something. (E.g. precisely because it is potential and not yet actual, the “meltedness” of the solid rubber ball can’t do anything.)
In light of Parmenides’ bifurcation, can somebody possibly come to reject premise 2, in that things are not changing — at least not from non-being to being? It seems like Parmenides and Aquinas are talking past each other. I await responses which describe what is meant by potency in relation to being and non-being. After all, ex nihilo, nihilo fit.
UPDATE: I think the answer lies in the definition of potency, which I discuss in introducing the theory of Dispositional Essentialism.
