Augustine on the immateriality of the mind

In Book 10, Chapter 10 of On the Trinity, St. Augustine argues for the immateriality of the mind.  You can find an older translation of the work online, but I’ll quote the passages I want to discuss from the McKenna translation as edited by Gareth Matthews.  Here they are:

[E]very mind knows and is certain concerning itself.  For men have doubted whether the power to live, to remember, to understand, to will, to think, to know, and to judge is due to air, to fire, or to the brain, or to the blood, or to atoms… or whether the combining or the orderly arrangement of the flesh is capable of producing these effects; one has tried to maintain this opinion, another that opinion.

On the other hand who would doubt that he lives, remembers, understands, wills, thinks, knows, and judges?  For even if he doubts, he lives; if he doubts, he remembers why he doubts; if he doubts, he understands that he doubts; if he doubts, he wishes to be certain; if he doubts, he thinks; if he doubts, he knows that he does not know; if he doubts, he judges that he ought not to consent rashly.  Whoever then doubts about anything else ought never to doubt about all of these; for if they were not, he would be unable to doubt about anything at all…

[T]he mind knows itself, even when it seeks itself, as we have already shown.  But we can in no way rightly say that anything is known while its substance [or: essence] is unknown.  Wherefore, since the mind knows itself, it knows its own substance [or: essence].  But it is certain about itself, as is clearly shown from what we have already said.  But it is by no means certain whether it is air, or fire, or a body, or anything of a body.  It is, therefore, none of these things…

For the mind thinks of fire in the same way as it thinks of air or any other bodily thing of which it thinks.  But it can in no way happen that it should think of that which itself is, in the same way as it thinks of that which it itself is not.  For all these, whether fire, or air, or this or that body, or that part or it thinks of by means of an imaginary phantasy, nor is it said to be all of these, but one or the other of them.  But if it were any one of them, it would think of this one in a different manner from the rest.  That is to say, it would not think of it by means of an imaginary phantasy, as absent things or something of the same kind are thought of which have been touched by the sense of the body, but it would think of it by a kind of inward presence not feigned but real -- for there is nothing more present to it than itself; just as it thinks that it lives, and remembers, and understands, and wills.  And if it adds nothing from these thoughts to itself, so as to regard itself as something of the kind, then whatever still remains to it of itself, that alone is itself.  (pp. 55-57)

Useful discussions of these passages can be found in chapter 6 of Matthews’ book Augustine, and, more recently, in Bruno Niederbacher’s essay “The human soul: Augustine’s case for soul-body dualism” in the considerably revised 2014 second edition of The Cambridge Companion to Augustine.  (The bracketed alternative translation of Augustine’s word for “substance” as “essence” is not my addition, by the way, but is in the McKenna/Matthews translation.  Matthews and Niederbacher both regard this translation of substantia as equally plausible or even more plausible in this particular context.)

In the first two paragraphs quoted we have a version of what is sometimes called “the Augustinian cogito,” insofar as Augustine prefigures (here and in Book XI, Chapter 26 of The City of God) Descartes’ famous Cogito, ergo sum.  You cannot coherently doubt that you live, remember, understand, will, think, know, and judge, since, Augustine argues, the very act of doubting that one does these things itself involves doing them. 

Of course, you could doubt that you “live” in the sense of having a metabolism, etc., insofar as you can wonder (as Descartes did) whether you are really a spirit divorced from any body and are merely hallucinating that you have one.  But what Augustine means here is that even in that case you couldn’t coherently doubt that you “live” in the sense of existing as a disembodied, thinking thing.

Augustine also notes that even if one is committed to some version of materialism according to which our mental powers are to be attributed to the brain, to atoms, to some particular kind of arrangement of the flesh, or what have you, one could still at least coherently doubt that this was the case in a way one cannot coherently doubt that one thinks, wills, etc.  In the remaining passages, Augustine develops this contrast in a manner intended to show that the mind cannot be material in these ways or any other way.  Of course, this approach to arguing for the mind’s immateriality also sounds very proto-Cartesian, though I think Augustine’s arguments here are not exactly the same as any of Descartes’.

Matthews plausibly suggests that, whether Augustine intended it or not, there are two distinct arguments to be found in the last two paragraphs quoted above.  Let’s consider them in order.  In the third paragraph the argument seems to me plausibly reconstructed in the following way (which, I should note, is not necessarily the way Matthews or Niederbacher would reconstruct it):

1. The mind knows itself with certainty.

2. But a thing is known only when its essence is known.

3. So the mind knows its own essence with certainty. 

4. But the mind is not certain that it is the brain, or atoms, or an arrangement of flesh, or anything else that is material.

5. So it is not part of the essence of the mind to be the brain, or atoms, or an arrangement of flesh, or anything else that is material.

What should we think of this argument?  I’m not certain, though some objections that might at first glance seem strong are not in fact decisive.  Matthews notes that functionalists claim that the mind could be realized in the brain but also in other material systems, such as a sufficiently complex computer.  Hence “a mind might know its own essence without knowing what matter it is realized in” (Matthews, Augustine, p. 46).  The point, I gather, is that while the mind can doubt that it is realized in this particular kind of matter or that kind, this may merely reflect the fact that it is realizable in multiple sorts of matter, and does not entail that it could exist apart from any matter at all. 

However, even apart from the deficiencies of functionalist theories of mind, this does not seem to me to be a good objection (though in fairness to Matthews I should emphasize that he considers this as an objection which might be raised against his own reconstruction of the argument, which is not exactly the same as mine).  Augustine’s point is not that there is something special about the particular examples he cites -- the brain, atoms, configurations of flesh, etc. -- that makes it possible for the mind to doubt that it is any of them.  His point is precisely that what is true of them is going to be true of anything material.  The mind, he could point out in response to our imagined functionalist, can doubt that it needs to be “realized” in anything material in the first place.  Even the functionalist would agree that it is at least possible coherently to doubt this, and that is all Augustine needs for the argument to go through (assuming it is otherwise unproblematic).

A functionalist may respond that it is also possible to doubt that the mind is realized in any postulated immaterial substrate.  But as I have pointed out when addressing parallel objections to Cartesian dualism (here and here), this sort of objection just completely misses the dualist’s point.  In Descartes’ case, he is not (contrary to the stock caricature) postulating a ghostly kind of stuff (“ectoplasm” or whatever) in which thought merely contingently inheres, so that one might coherently suppose it possible in principle for the one to exist apart from the other.  For Descartes, the res cogitans is not merely a substrate which underlies thought, but just is thought.  There is no conceptual space between them by which the functionalist might pry them apart.  Augustine, it seems, is saying something similar.  In knowing with certainty that it thinks, wills, understands, etc., the mind knows its essence, not merely activity contingently related to that essence which might in principle exist apart from it.

Matthews also notes that a critic may object to the claim that a thing is known only when its essence is known.  He cites Aristotle’s example of thunder, which one could know is a noise in the clouds even if he does not know the essence of thunder.  Or we might note that someone could obviously know that water is the liquid which fills lakes and oceans and falls from the sky as rain even if he does not know that water is H₂O. 

This is a stronger objection, but in reply it could be noted that premise 2 may not actually be essential to the argument.  Augustine need not claim of everything that when it is known, its essence is known.  Perhaps he could simply argue that this is true of the mind, specifically.  For as Niederbacher emphasizes in his discussion of this argument, Augustine takes the mind to have a special immediate access to itself that it does not have to other things.  (Hence Niederbacher calls the argument under discussion “the cognitive access argument.”)  In the preceding chapter, Augustine had written that “when it is said to the mind: ‘Know thyself,’ it knows itself at the very instant in which it understands the word ‘thyself’; and it knows itself for no other reason than that it is present to itself” (On the Trinity, Book 10, Chapter 9, p. 54).  The idea might be that absence of certainty is possible only where our access to a thing is not immediate.  For example, we can be less than certain about the things we see because our access to them is mediated by light, the optic nerve, stages of neural processing, etc., and this opens the door to the possibility of illusion and hallucination.  But the certainty that the “Augustinian cogito” shows that the mind has vis-à-vis itself implies that its access to itself is not mediated.

So, it may be that, given Augustine’s view about the mind’s immediate access to itself, it is steps 3 - 5 that are the really essential ones in the “cognitive access argument,” and the problematic premise 2 can drop out as inessential.  The basic idea would be that given the mind’s immediate access to itself, it has a certainty about its essence that it does not have about whether it is the brain, atoms, etc., so that nothing of the latter, material sort can be part of its essence.

But this brings us close to the thrust of the argument of the last passage from Chapter 10 quoted above, which Matthews judges to be not only a distinct argument but a stronger one.  In this passage, Augustine says of “fire, or air, or this or that body” that we think of them “by means of an imaginary phantasy,” or mental image.  But Matthews suggests that whether we always make use of mental images, specifically, when we think of material things is not really essential to Augustine’s point.  What is essential is rather the claim that we always make use of mental representations of some sort or other.  Thus the mind’s cognitive access to material things is always mediated in a way Augustine thinks its cognitive access to itself is not. 

Thus we have what I take to be a plausible reconstruction of the overall thrust of the reasoning of the last passage from chapter 10 quoted above:

1. The mind knows itself directly, without the mediation of a mental image or any other representation.

2. But the mind knows material things only via the mediation of a mental image or some other representation.

3. So, the mind is not a material thing.

In defense of premise 1, Augustine would, again, presumably say that if we were to deny it, then we would be faced with the possibility of skepticism about the mind’s own existence.  Yet the “Augustinian cogito” shows that such skepticism is impossible.  So we must affirm premise 1.

In defense of premise 2, we could note that, apart from eliminative materialists, materialists themselves tend to affirm that all thought takes place by means of mental representations of some sort (whether “sentences in the head,” distributed representations, or whatever).  Hence they cannot consistently reject premise 2.  Augustine and materialists of the sort in question are essentially in agreement that in general, thought involves mental representations.  The difference is just that Augustine thinks the “Augustinian cogito” shows that there is an exception in the special case of the mind’s knowledge of itself. 

As Matthews notes, a critic might still object to premise 1 on Freudian grounds.  It might be claimed that in the case of unconscious mental states, the mind knows itself (insofar as it discovers that it has a repressed desire of some sort, say) but that it does not do so directly (since the desire is unconscious).  But as Matthews also notes, this wouldn’t really be a strong objection.  Much of the talk about “unconscious” mental states seems to me pretty loose.  John Searle argues that to attribute a so-called “unconscious mental state” to someone is really just to attribute to him a neural state with the capacity or disposition to cause a conscious mental state.  This seems to me essentially correct.  What is strictly mental is the conscious state caused by the neural state, so that we don’t really have a counterexample to the claim that the mind always knows itself directly.

Given Augustine’s emphasis on the mind’s direct and certain knowledge of itself, the arguments we’ve been examining have, as I have said, a clearly proto-Cartesian flavor about them.  It is worth noting, though, that whatever one thinks of it, Augustine’s reasoning is not the same as that of Cartesian “conceivability arguments” (which I have discussed critically here and here).  There is no attempt to read off, from what we can conceive, conclusions about mind-independent reality, after the fashion of rationalist metaphysics.  The introspective approach to the study of the mind that Augustine shares with Descartes has no essential connection with Cartesian/Leibnizian rationalism.