Aquinas on Powers --- One Interpretation (3)

In the last post, I tried to buttress Aquinas's (alleged) argument that the soul and its powers cannot be one and the same because I always have a soul, whereas I do not always exercise my soul's powers (there are times when I sleep, for instance, when I do not think). I further pointed out in the last post that each of the soul's powers require different circumstances for their actualization, and that provides another reason to say that the soul's powers must be distinct from each other (and, consequently, from the soul itself).

Now, suppose that we grant this. Still we might wonder: what sorts of things are the soul’s powers? According to Aquinas, they are qualities of the soul, perhaps similar to the way that a pale skin color is a quality of Socrates.

Of course, to compare the soul’s powers to the color of Socrates’ skin might suggest that the soul’s powers can be gained and lost, just like the color of Socrates’ skin. After all, Socrates’ skin color can change --- as would happen, say, if he went to the beach and got a tan. So surely the soul’s powers can change too.

But Aquinas rejects this, insisting instead that although the soul’s powers are qualities of the soul, they cannot be gained and lost in the way that Socrates’ skin color can. On the contrary, the soul’s powers are not the sorts of features that can ‘come and go’. Rather, they are permanently attached, so to speak, to the soul itself (so long as the soul exists).

I should note that Aquinas does not, so far as I know, ever offer an argument for the claim that the soul’s powers are qualities. But he did make this claim more than once throughout the course of his career, so I think we can safely assume that Aquinas is firmly committed to the idea that every human soul is accompanied by a set of distinct powers (qualities) that are permanently attached to it (so long as that soul exists).

One could easily take these ideas from Aquinas and generalize them. That is, one could easily insist that any power must be distinct from its basis when the thing that has the power in question also has its basis for any period of time when that power is not exercised. So, that is one interpretation of Aquinas's theory of powers.

Aquinas on Powers - One Interpretation (2)

In the last post, I mentioned that part of me thinks Aquinas's arguments about powers really boil down to a simple argument from identity: if A and B are identical, then anything true of the one must be true of the other, but since this is not the case with my soul and its powers (I always have soul, for instance, but I am not always thinking), it follows that my powers that are based on my soul must be different from my soul itself.

But one could buttress this argument even further. For we might point out that one of the characteristics of powers is that they can only be exercised in particular circumstances. For instance, wine glasses can be broken when they are dropped on a hard floor (in a world consisting only of soft cushiony floors, wine glasses would not break when dropped). Wine glasses might also be broken when they are struck with a swinging baseball bat. And so on.

We might then point out that each power of my soul is no different. Each power of my soul requires a different set of circumstances for its exercise too. For example, compare my power of sight with my power to remember things I have already seen. According to Aquinas, both of these are powers of my soul. However, it would seem that the former power can only be exercised in one set of circumstances (I must have my eyes open, there must be sufficient light, and so forth), whereas the latter power requires an entirely different set of circumstances (e.g., that what I saw before was adequately stored in my memory banks, and so forth).

Consequently, we might make the following inference: since each power of my soul requires a different set of circumstances for its exercise, it follows that each power of my soul must be distinct from every other power of my soul, and from my soul itself. Otherwise, I could not exercise one of my soul’s powers without exercising all of them at the same time. So, one might say, surely it follows that my soul and each of its powers must be distinct from each other.

Aquinas on Powers - One interpretation (1)

Throughout his career, Aquinas maintained that a human soul cannot be identical to its powers. I have translated a number of his arguments for this view (see the previous three posts), but I'm not sure I understand any of those arguments.

Part of me thinks that much of Aquinas's reasoning here boils down to the following simple argument: although I always have a soul as long as I exist, my soul’s powers are exercised only some of the time. For instance, so long as I am alive, I have a soul, but there are times in my life when I do not think, when I do not love, and so on. Consequently, my soul cannot be identical to any of my powers to perform these operations.

This is, of course, a simple argument from identity. That is, if any A and B are identical, then anything true of the one must be true of the other. But since this is not the case with my soul and its powers (for I always have a soul as long as I exist, but I do not always exercise my soul’s powers), Aquinas concludes that they must not be identical. Whatever my soul is then, it must be distinct from my power to think, my power to love, and so on.