The trouble is that that is not what the materialist is saying. The matter to which he would reduce everything is not the matter of common sense, not the hard earth of daily experience. It is instead a highly abstract theoretical construct which – just like Descartes’ res cogitans – is not and indeed cannot be known directly via perception (nor, unlike the res cogitans, by introspection either). Moreover, it is a conception the materialist has inherited from Cartesian dualism itself. And it is that conception of matter, rather than the Cartesian’s commitment to a non-empirical res cogitans, that has made it so difficult for Cartesians and materialists alike to account for how conscious awareness relates to the physical world.
Longtime readers of this blog will recognize these themes. They are also among the themes of philosopher William Barrett’s interesting 1986 book . Barrett writes:
Oddly enough, the trouble with the Cartesian dualism comes from the side of the body. The body, as Descartes conceives it, is not such that it can accommodate the soul. It cannot, so to speak, be penetrated by the soul; it can only remain in external contact with it. This body is not the physical body, our physical body, as we know it in our daily intimacy with it. It is the body of physics – that is, of the science of physics; a piece of matter, and particularly as Descartes conceived of matter. But the body of physics is remote and unknown to us and is not the body we live in in our day-to-day existence. The body we know is rarely sharply distinguishable from the soul: in our moods and feelings we are not often sure what part is physical and what not. There is no sharp dividing line between. The life of flesh and blood is particularly focused about the feelings and emotions. So long as there is no adequate conception of the concrete or lived body, our theories of mind cannot deal adequately with the life of feeling. (pp. 19-20)
Let’s pause over the second half of this passage. Consider the feelings and emotions people experience every day – the warmth in the throat that results from a swig of hot coffee, a twinge of pain in the knee or lower back, an itch from a rash that won’t go away, a pinch from tight clothing, the twinge of excitement that spikes in the chest upon being startled, the tightness and heaviness in the chest that can result from worry or depression, the uncomfortable fullness that results from having overeaten, the pressure of having too full a bladder or colon, the agitation of sexual arousal, anxiety, fear, or anger, and so on. All of this is experienced as bodily. It has the feel of knowing a particular bit of matter from the inside, as it were, from a place deep within the marrow and viscera. If you were unacquainted with the way modern philosophers talk and one of them told you that these features of daily life were “mental” or “in the mind,” you would suppose that what he meant is that they were somehow unreal or imaginary, which sounds crazy.
But that they are in the mind rather than in the body is precisely what post-Cartesian philosophers, whether dualist or materialist, do say. They take matter to be devoid of anything but primary qualities such as size, position in space, motion, and in general what can be given a purely mathematical characterization. Anything else is treated as merely a projection of consciousness. Hence the redness, sweetness, fragrance, and crunchy sound of the apple are taken to be nothing more than the qualia of our experience of the apple, and not to correspond to anything in the apple itself. And in the same way, warmth, pain, itches, twinges, sensations of pressure, tightness, fullness, arousal, and the like are taken to exist only as the qualia of our conscious experience of the body, and to reflect nothing in the intrinsic nature of the body itself. The matter of the apple and that of the body alike are taken to comprise nothing more than colorless, odorless, tasteless particles moving through space. The purely mathematical description of matter afforded by particle physics exhausts their nature.
Hence, on this view, introspection no more reveals to you the nature of the flesh than perception reveals to you the nature of the apple. Apple and flesh alike are strictly unobservable. What we perceive and introspect are really just the mind’s representations of the apple or the flesh, and not the real McCoy. Physical theory, as interpreted through a mechanistic philosophy of nature, tells us their real nature.
Now, Berkeley had a field day with this picture of matter and our knowledge of it. Though he famously denied the reality of matter, the matter he denied was already a pretty ghostly thing anyway – matter stripped of all the concrete reality perception and common sense attribute to it, leaving only a desiccated mathematical husk. And Berkeley’s point was in part that there is nothing left for the mathematical structure described by physics to be the structure of when all of those concrete features are abstracted away.
We are accustomed to treating Berkeley’s philosophy as slightly (or more than slightly) mad, when the truth is that he was merely drawing out the implications of the mad conception of nature bequeathed to him by Descartes, Locke, and company. As Barrett writes:
The real world of our common experience contains trees, grass, singing birds; houses and other people; chairs and tables; etc., etc. In our daily life these are evidently and substantially there, and not at all “subjective” appearances of something else; and for Berkeley, too, they are evidently and substantially there. It is Locke who would undermine their reality, and make it secondary to some underlying abstractions of physics. And here Berkeley turns Locke’s own empiricist weapons back upon their originator. (p. 39)
Specifically, Locke and company had appealed to the way that the appearances of color, sound, and the like are relative to the perceiver as a reason to judge them mere secondary rather than primary qualities of matter. Our ideas of motion, position in space, etc. correspond to something really out there in mind-independent reality, but our ideas of color, sound, etc. do not. Berkeley argued that the appeal to relativity can be deployed against all the so-called primary qualities as well. And that includes what the Newtonians naively took to remain objectively out there after the mechanists were done with their desiccation of matter. Here Barrett is worth quoting at length:
Here Berkeley introduces the principle of relativity in a bold and thoroughgoing form that was not to emerge again until Einstein in the twentieth century.
The motion or rest of material particles had been taken as absolute by Locke because there was the absolute space of Newton in which they moved or remained at rest. And here Berkeley performs one of his most audacious acts of analysis, as he seeks to pull down one of the sacred pillars of the Newtonian world. Space – the absolute space of Newton, container of all that is – is not given as a reality in and of itself. It is built up as a high-level abstraction from our perceptions of touch and vision. It is derived from experience; it is not the container of experience. We invert the proper order by taking the abstraction as a concrete reality.
In sum, the whole world of matter, which Locke would make the substratum, or underlying reality, for the world of our common experience, is in fact a high-level intellectual construction. It is a case of misplaced concreteness, as the philosopher A. N. Whitehead in our century has called it: the abstract concepts of physics are taken as ultimately concrete in place of the ordinary world of common experience. Berkeley stands with this ordinary world, and he consistently reassures his ordinary reader that he is on his side against the materialism of sophisticated philosophers. (p. 40)
The trouble, of course, is that Berkeley himself is not entirely the friend of common sense, to say the least. For he denies that tables, chairs, and the like continue to be there when no one perceives them, and that thesis is no part of common sense. Like common sense, Berkeley holds that there is no real distinction between primary and secondary qualities. But whereas common sense takes all of these qualities to be out there independent of the mind, Berkeley takes them all to be equally mind-dependent. Like his philosophical predecessors, he buys into the basic move of the moderns, which is to relocate the qualities of physical objects into the mind. It’s just that, unlike those predecessors, he relocates all of them there. Hence even Berkeley is in fact insufficiently radical in his critique of his predecessors, precisely because he is insufficiently reactionary.
Barrett makes the important point (at pp. 40-41) that the contemporary materialist’s obsession with the computer model of the mind in no way remedies the tendency of the modern conception of matter to collapse matter into mind. For the notion of a computer is itself the notion of something essentially mind-dependent. Nothing counts as hardware or software apart from an intelligence which has designed them to function as such. (This is a theme that John Searle would go on to develop in detail a few years later, in argumentation that I have discussed and defended at length elsewhere.)
When I say that the moderns either partially or wholly move the qualities of physical objects into the mind, what I mean, to be more precise, is that they move them into the intellect (albeit the empiricists on the list, unlike Descartes, collapse the intellect and the imagination, but put that aside for present purposes). That is why Descartes notoriously takes non-human animals to be insensate automata. They lack rationality, hence they lack a res cogitans. Thus, since for Descartes the only other kind of substance there is is res extensa, which is pure extension devoid of any consciousness, that is what animals must be.
This too is contrary to the commonsense conception of matter. Consider again what you experience in your own body, and experience precisely as bodily phenomena – sensations of warmth, flashes of pain, twinges of excitement, arousal, fear, and anger, and so on. Common sense takes something like all this to exist in dogs, horses, bears, and other non-human animals, even though these creatures lack rationality and are entirely corporeal in nature. For again, from the point of view of common sense, these features are bodily in nature, not mere representations in the intellect, so that other bodily but non-intellectual creatures are as capable of exhibiting them as we are.
Some contemporary philosophers, cognizant of the problems with the early modern mechanistic and mathematicized conception of matter, have reinserted into matter the qualities common sense attributes to it, but then fallaciously draw the conclusion that this entails panpsychism. They are making a mistake similar to Berkeley’s, and like him they are insufficiently radical precisely because they are insufficiently reactionary, accepting as they do too much of the modern conception of matter they claim to be rejecting. For like the early moderns, they take the qualities of ordinary physical objects to be partially or wholly mind-dependent, i.e. to be identified with the qualia of conscious experience. Unlike the early moderns, they take these qualities to exist in physical objects themselves, and not just in our minds. The result is that they conclude, absurdly, that there must be something analogous to conscious awareness even in rocks, dirt, tables, chairs, etc. (The poor moderns. They just can’t do anything right!)
Another part of the problem is that they implicitly buy into the modern reductionist idea that all matter is essentially of the same one type. Hence if there really is consciousness in the matter that makes up non-human animal bodies, then (the fallacious implicit inference goes) there must be something like it too in rocks, dirt, tables, chairs, etc.
The sober, boring truth – enshrined in Aristotelian philosophy and common sense alike – is that some kinds of purely material substances (namely non-human animals) are conscious, and others (like rocks and dirt) are not. The latter really do possess qualities like color as common sense conceives of it, but that does not entail panpsychism, because (contra Descartes, Berkeley, and company) those qualities are not entirely mind-dependent. Not all matter is reducible to one, lowest-common-denominator type, and none of it is reducible to the purely mathematical description afforded by physics. That description is merely an abstraction from concrete physical reality. It captures part of that reality, to be sure, but not the whole of it.
To think otherwise is somewhat like thinking that “the average person” of the statistician really exists, but that the various individual people we meet from day to day do not. The reality is that those individuals do exist, and that the notion of “the average person,” while it captures important aspects of reality and is therefore useful for certain purposes, is a mere abstraction that does not correspond to any concrete entity. And in the same way, the concrete physical objects of everyday experience also really do exist, whereas the mathematical description afforded by physics, despite its undeniable predictive and technological utility, does not capture the entirety of concrete reality. To pretend otherwise is, we can agree with Berkeley, a kind of make-believe.