Fodor and Aquinas on the Extended Mind Thesis

Jerry Fodor reviews Andy Clark’s Supersizing the Mind. Clark, with David Chalmers, has defended what they call the “Extended Mind Thesis” (EMT), according to which the traditional distinction between the mind and the world is less clear-cut than is usually supposed. There are cases where purportedly “external” objects are (so the EMT claims) really parts of a mind. For example, the notebook in which you keep your friends’ addresses and phone numbers would on this view literally be as much a part of your mind as your memory of your own address and phone number. For in its relations to the rest of your mental life and to your behavior, it functions the way your memory does. Chalmers tells us his new iPhone is, similarly, literally a part of his own mind. And so forth.

If this strikes you as odd and implausible, Fodor agrees, and in typical Fodor style he deconstructs the EMT with clarity, elegance, and humor. Take a look. But in the spirit of Thomas Aquinas, who always sought to discern whatever kernel of truth might be hidden in even the most implausible views, let me note one respect in which the EMT might at least be gesturing in the direction of an important truth.

The EMT is part of a broader trend in recent philosophy of mind called “externalism,” which comes in many varieties but has at its core a critique of the Cartesian “inner theatre” conception of the mind as a realm of subjective, self-contained facts metaphysically sealed off from the “external” world. This conception has dominated philosophy since Descartes, in the thinking of empiricists and rationalists, materialists and dualists alike. The externalist reaction is motivated in part by a desire to overcome the epistemological and semantic gaps that the Cartesian picture notoriously opens up. If all we ever have direct access to is the subjective realm of the mind, how can we know that any external world really exists? Worse, how can we so much as form meaningful thoughts about it?

The externalist suggests various ways in which aspects of the so-called “external” world actually determine, or even constitute, the contents of our thoughts, so that the subjective/objective or internal/external divide is nowhere near as absolute as the Cartesian picture implies. Contemporary writers like Hilary Putnam, John McDowell, and Robert Brandom began this revolution (in their very different ways), inspired by hints found in writers like Sellars and Wittgenstein. (When I was in grad school, externalism was all the rage. It seemed you couldn’t walk into the men’s room at UC Santa Barbara without overhearing someone muttering about it from behind the partition. I might be exaggerating slightly.)

From the point of view of Thomists, who generally regard the Scholastic-to-modern transition as an across-the-board tragedy (philosophically-speaking, that is – no one denies that modern science has made tremendous advances), all of this is very salutary indeed. Still, from a Thomistic point of view, even the externalists are sometimes insufficiently anti-Cartesian. For their accounts still often smack of the idea that the mind-world relationship is essentially about the former “representing” the latter.

To be sure, externalists often regard themselves as critics of the “representationalist” picture of the mind, where this picture involves positing inner “representations” which either mirror or fail to mirror various aspects of external reality. Given this picture, the traditional epistemological-cum-semantic problem can be summarized in the questions: How can we know whether the inner representations mirror external reality accurately? What is the source of the “intentionality” possessed by these representations, in virtue of which they count as representations in the first place? Externalists like McDowell counter this picture with the suggestion that there is no gap between the mind and what it represents in the first place; when I truly think about the teacup next to me, the teacup itself is in a sense a constituent of my thought about it rather than something external to the thought. There is no epistemological or semantic gap between the thought and the cup that needs to be bridged, for the thought just wouldn’t be the thought that it is without the presence of the cup. (Various complications are added to the story in order to deal with cases of hallucinatory cups and the like.)

But as (the non-Thomist) Michael Lockwood notes in a sympathetic critique of this approach in his book Mind, Brain, and the Quantum:

Even if the mind is, so to speak, tucked up in bed with its objects, still it seems to me a mystery how its thoughts come to be about those objects. Making the object which a thought is about literally a component of that thought obviates the problem of reference only if one somehow thinks it unproblematic that an object should, as it were, mean itself. (p. 147)

Or, to put the point another way (and perhaps a way Lockwood would not put it himself) if one regards external objects mechanistically, as devoid of final causes or intelligible natures or essences, then they will be as inherently devoid of meaning or intelligibility when you “tuck them up in bed” with the mind as they were when conceived of as external to the mind.

Similarly, while McDowell speaks of the “space of causes” and the “space of reasons” – that is to say, of the world conceived of as governed by physical law, on the one hand, and of the intentional-cum-rational structure of thought on the other – as coming together in the human organism, how exactly this is supposed to work remains mysterious if one is beholden to a broadly mechanistic conception of the material world. If a dualist interpretation is rejected (as McDowell would reject it) the claim that human beings are governed both by physical law and by irreducibly intentional-cum-rational thought processes seems obscurantist. In particular, the externalist project can come to seem to rest on uncashed and uncashable metaphors – uncashable, anyway, in the coin of natural processes conceived of mechanistically.

The way to salvage the very real and deep insights of (some forms of) externalism is, for the Thomist, via a more thoroughgoing rejection of Cartesianism. In particular, it requires a rejection of the 17th century mechanistic revolution in philosophy of nature that opened up the epistemological-cum-semantic gap between mind and world in the first place (and, as I argue in The Last Superstition, opened up countless other philosophical problems – often called “traditional” but really just modern – as well). When the natural world is seen to manifest final causality from top to bottom anyway, the intentionality that characterizes the human mind no longer stands out as something poking out from the Procrustean bed, in need of either cramming back under the sheets or lopping off altogether.

More to the present point, when the objects that make up the material world are seen to possess substantial forms or essences, the kernel of truth in the externalist metaphor of the mind and world “interpenetrating” each other stands revealed. For on the Aristotelian-Thomistic account of knowledge, when the intellect comes to understand some object, what this essentially involves is the form that makes the object what it is coming to reside in the intellect itself. It isn’t that a “representation,” understood as a kind of internal object or particular, comes to exist in the mind and in some way mirrors or correlates with the (utterly distinct) thing outside the mind; it is that one and the same thing, the object’s form or essence, exists simultaneously in the intellect and in the object known by the intellect. They are formally identical and thus not utterly distinct. (It is because the intellect can thus take on a form without becoming the sort of thing that the form is a form of that, for Aristotle and Aquinas, the intellect must be immaterial. For when a material thing takes on a form, it necessarily does become the thing the form is a form of. For example, for a material thing to take on the form of a dog or a triangle just is for it to become a dog or a triangle, while the intellect can take on these forms without becoming either a dog or a triangle.)

The analytical Thomist John Haldane calls this the “mind-world identity theory,” for as Aquinas says in his commentary on Aristotle’s De Anima, “the soul is in a way all things” insofar as it takes on the forms or essences of the things it knows, which could in principle be anything. But as the “in a way” indicates – and as the previous paragraph implies – the “identity” in question here is formal identity rather than identity full stop. The intellect isn’t identical to the dog it knows when it knows a dog, but since the same form or essence exists in the intellect and in the dog, there is at least an identity of form, since one and the same form exists in both places.

But is any of this really any better than what contemporary externalists have said? For isn’t this talk of something existing “in” the intellect itself metaphorical? It is not. Here we need to resort instead to Aquinas’s famous doctrine of analogy. When I “see” that the Pythagorean theorem is true, I obviously do not see it in the same sense in which I “see” the teacup on the floor next to me. The senses involved in these cases are not univocal. But neither are they equivocal or totally unrelated, as the sense of “see” in a reference to the Vatican as the Holy See is totally unrelated to “see” as used in the case of seeing the cup or seeing the truth of the theorem. Rather, the senses involved are analogous: there is in the event of seeing the truth of the theorem something analogous to the seeing of the cup. In the same way, the sense in which a form is “in” the dog is analogous to the sense in which the same form is “in” the intellect which knows the dog.

One of the themes of The Last Superstition is how frequently contemporary philosophers misinterpret the arguments made by Aristotelians and Thomists, because they tend inadvertently to interpret Aristotelian-Thomistic references to “cause,” “essence,” “matter,” and many other key concepts as if they meant more or less the same thing that modern philosophers mean when they use such terms. They forget, if (apart from those who have made a serious study of the history of their discipline) they ever knew, that the mechanistic revolution entailed a radical redefinition of most of the key concepts of traditional metaphysics. As Gyula Klima has emphasized in a series of important papers, a related problem is that contemporary commentators on medieval arguments in philosophy of religion, philosophy of mind, and metaphysics are often unaware that these arguments presuppose a set of logical and semantic doctrines that are very different from but every bit as sophisticated and worked-out as those taken for granted by post-Fregean philosophers. Aquinas’s doctrine of analogy is a key example.

The conceptual revolution the Thomist would recommend is thus almost as radical as that entailed by the Scholastic-to-modern transition itself. (I say “almost” because it does not entail abandoning modern science wholesale and returning, say, to pre-modern physics and chemistry, but rather abandoning the assumptions that have come to define modern philosophy – albeit this would certainly require a reinterpretation of the philosophical significance of modern science.) But nothing less than such a radical revolution is required if the place of mind in the natural world is properly to be understood, because it was the Scholastic-to-modern transition that made that relationship problematic in the first place. (Indeed, nothing less is required if most of the so-called “traditional” problems of philosophy are to be solved, or so I argue in TLS.)

(N.B. Readers interested in an extended discussion of the relationship between the Thomist and externalist approaches to these matters are advised to take a look at John O’Callaghan’s book Thomist Realism and the Linguistic Turn.)