Act and potency

James Chastek of Just Thomism suggests: “A thomist could probably teach the whole history of modern thought as an overlooking of the distinction between potency and act.”

Well said. Readers of this blog and of The Last Superstition have known me to identify the abandonment of final causes as the original sin of modern philosophy. But one might just as well bang on the act and potency drum, as the Neo-Scholastics did, and as I do myself in much of TLS. For the notions are deeply interrelated: A potency or potential is a potency for some act or actuality, toward which it points as an end; and to have an end is to be in potency towards it. It is not for nothing that the very first of the famous Twenty Four Thomistic Theses is: “Potency and Act divide being in such a way that whatever is, is either pure act, or of necessity it is composed of potency and act as primary and intrinsic principles.”

Now, one does find echoes of the Aristotelian-Scholastic doctrine of act and potency in some of the early moderns. That God is Pure Actuality is a thesis taken for granted in Descartes’ Third Meditation. Leibniz, for my money the greatest of the moderns, makes a valiant attempt to salvage for them the Aristotelian final cause/efficient cause and act/potency distinctions. But it couldn’t last, and with the rise of empiricism these fragments of ancient wisdom (like pretty much all wisdom, when one becomes an empiricist) get sucked down the memory hole almost irretrievably.

So what? Well, for starters, you can’t understand Aquinas’s First Way, the argument for an Unmoved Mover – which he judged to be the most evident of the arguments for God’s existence (rightly, I increasingly think) – unless you understand the act/potency distinction. More importantly, you can’t understand why the argument works, and is ultimately immune not only to the standard caricatures but even to more serious and worthy objections, unless you understand the act/potency distinction. (I defend the argument in TLS, and in much greater depth and without all those nasty polemics, in the forthcoming Aquinas.)

Nor can you understand how contemporary (e.g. Kripke-Putnam) essentialism differs from real essentialism (i.e. the Aristotelian kind) unless you understand the act/potency distinction. For example, when it occurs to you that Terri Schiavo could not exercise the power of reason given the brain damage she had suffered, you might start to wonder whether rationality is part of the essence of human beings after all. For here is a human being who (so it is claimed) lacks reason; therefore (the modern “essentialist” might conclude) reason must not be essential to being human. But when you keep in mind the distinction between act and potency – in particular, when you recall the distinctions between first and second actuality and first and second potentiality explained on your favorite page of TLS – you see that this simply does not follow at all.

I quote myself (somebody has to do it):

‘A thing’s various actualities and potentialities exist in a layered fashion and constitute a hierarchy, as I will now demonstrate with a paragraph full of somewhat dry technical distinctions. (Bear with me.) Since you are a human being, you are a rational animal; because you are a rational animal, you have the power or faculty of speech; and because you have this power, you sometimes exercise it and speak. Your actually having the power of speech flows from your actually being a rational animal; it is a “secondary actuality” relative to your being a rational animal, which is a “primary actuality.” And your actually exercising that power on some occasion is in turn a “secondary actuality” relative to your having the power – which, at least relative to the actual exercise of it, is “primary.” (Note that you have the power even when you don’t exercise it, e.g. when you are sleeping or competing in a breath-holding contest.) There are similar distinctions to be drawn with respect to potentiality. Suppose you don’t speak German. You nevertheless have the potential to speak it, in the sense that you might learn it. Call this a “first potentiality” for speaking German. Now, even once you do learn it, you won’t of course be speaking it all the time, even though you could speak it at any particular moment if you wanted to. You thus now have the potential to speak German in another sense. Call this a “second potentiality” for speaking German. Now acquiring this second sort of potentiality for speaking German – the ability to speak it at will – is also, of course, a kind of actuality, insofar as you now actually have the ability to speak it. So a second potentiality is also a kind of primary actuality; and when you really do go ahead and speak German, exercising your new ability, the act of speaking counts as a secondary actuality relative to this primary actuality. I could make further distinctions – and I know you want me to – but that’s enough to make the point.’ (The Last Superstition, p. 56)

Now you know why I included the polemics. Had to find some way to keep the reader awake. (In case you recently ordered the book from Amazon and are now in a state of panic, wondering whether you can still cancel, I suppose should add that I have chosen to quote the single dullest passage in the entire near-300 page opus. The theory is that the still undecided buyer will think “Hmm, well, I guess the rest could only be better!”)

Anyway: The point of all this is that it is too simple to ask whether (say) “rationality” or “language” or “actual episodes of thought” are essential to being a person, or a human being, or whatever, full stop. We need to consider that these various characteristics are related in a layered fashion, and can exist either “in act” (or actually) or “in potency” (or potentially), where the potentials in question are grounded in the actualities.

To apply all this to the case at hand: Terri Schiavo, like every human being, is a rational animal as a primary actuality. And this remains true if she is impeded, by the damage to her brain, from exercising the various capacities that normally follow upon rational animality as secondary actualities. Put another way, in being a human being at all she has a first potentiality for speech, episodes of thought, and the like. When her brain is in good working order she also has a second potentiality for these capacities. But when it is damaged, though she loses this second potentiality, the first potentiality remains. That is precisely why, had regenerative treatments had been available, the second potentiality would have returned. What made her different from a “vegetable” or a mere animal is that these things never even have or could have rational animality as a primary actuality, and never even have or could have the capacity for speech, episodes of thought, etc. as a first potentiality. All told, Terri is neither a potential rational animal, nor a former rational animal, but an actual rational animal who has been frustrated in realizing her potentials. Vegetables and animals, by contrast, are never rational animals at all. They don’t “fail” to realize the potential for speech, episodes of thought, etc., because unlike even a brain damaged human being, they never have those potentials in the first place.

The relevance to abortion should be obvious. A fetus too isn’t a potentially rational animal or a potential person. A fetus is an actual rational animal and thus an actual person who hasn’t yet realized all his potentials. Etc.

Here is another reason, then, why the act/potency distinction is so important: without it we can be led into moral error as serious as the murder of innocent persons, as in abortion and infanticide.

And that’s just for starters. To paraphrase Wittgenstein, a cloud of philosophical error, indeed the entire Hurricane Katrina of error that is modern philosophy, is condensed in this one basic mistake of overlooking the act/potency distinction. The history of modern thought – indeed of modern civilization – is a history of the gradual “actualization” of all the unhappy potentialities that lie coiled in this primal error.

(For those readers interested in a refresher on act and potency, you can’t beat this chapter from Reginald Garrigou-Lagrange’s Reality: A Synthesis of Thomistic Thought.)