Over matter?

Mind

A Brief Introduction John R. Searle

Oxford University Press, $26, 326 pp.

This book succeeds in introducing clearly and succinctly the basic concepts, theories, and controversies of contemporary Anglo-American philosophy of mind, all without oversimplifying. Mind is perhaps less fun to read than Colin McGinn's comparable The Mysterious Flame: Conscious Minds in a Material World (see "Mind Matters," May 19, 2000), but Searle's book is more comprehensive and rigorous.

The central question in the philosophy of mind is what is called the mind-body problem. There are in fact two conundrums that go by this name. The first is the problem of mental causation: How are we to understand that the mind, which the seventeenth-century philosopher Descartes presented as immaterial, should be able to act on matter, first and foremost the brain, then this brain's body, and finally everything else? The second mind-body problem, which agitates many philosophers today, arises from approaching the problem from the opposite direction, namely, from body to mind. Here it is assumed that the only reality that exists is material or physical reality: the doctrine of materialism or physicalism, which Searle correctly notes has become something like "the religion of our time, at least among most of the professional experts" who think about the mind. The conundrum now is how to make sense of the fact that mindless, meaningless physical particles have given rise to minds like ours, possessed of consciousness and what philosophers call intentionality (meaning, simply put, that our consciousness is typically of or about this or that). To put the question as McGinn does in The Mysterious Flame, How are we to fathom the fact that "the squishy gray matter in our heads ... can be the basis and cause of a rich mental life"? Searle's presentation is not as dramatic, but the same conundrum takes center stage. In his words, "[H]ow do we fit into the rest of the world? How does the human reality relate to the rest of reality?"

Searle opens his book with a brief history of the mind-body problem, titled "Descartes and Other Disasters," but quickly turns to the present day. To give some of the history that Searle does and a little more: Descartes argued that the mind is a substance apart from the material universe. The fact that we happen to be "mingled" with bodies of our own must be acknowledged, but defies understanding. Descartes also denied that nonhuman animals have minds. Moreover, he pegged the meaning of the word soul (in Latin anima) to the meaning of the word mind, with the upshot that animals have neither minds, nor souls. In other words, for Descartes, animals are not truly animated, which for Aristotle and the scholastics meant possessed of a principle of life, particular to each but found in a hierarchy of forms. Instead, animals are supposed to be wholly understandable in terms of matter in motion. It is worth noting finally that, by dividing "body" and "mind," Descartes enabled mathematical physics--of which he was a founding figure, and which his philosophical writings were intended to serve--to go to work on the material universe without having to worry about how to account for the "inwardness" that characterizes our bodily lives. So Descartes's dualism was no disaster for modern physics.

As Searle recounts, many twentieth-century Anglo-American philosophers, put off by the logical absurdities of dualism, impressed by the triumphs of the physical sciences since the seventeenth century, and inspired by the prospects of the new "sciences of the mind" bringing to light correlations between the workings of the brain and mental phenomena, came to deny what is called the "irreducibility" of these phenomena in human beings. These philosophers denied, that is, that the mental phenomena you are experiencing this moment cannot, in principle, be wholly understood as points of mass/energy in fields of force (the twentieth-century descendant of Descartes's matter in motion). For the so-called identity theorists, for example, consciousness just is--it is identical with--a biological brain process, however complex this process may prove to be. In brief, twentieth-century materialists sought to analyze human beings as Descartes analyzed all other animals.

The problem with the identity theory and other materialist theories is that they seem to conjure away the phenomena that they claim to illuminate. As Searle observes, consciousness may well be a brain process, but it cannot sensibly be identified "with a neurobiological process, neurobiologically described." Against the identity theory and other materialist explanations, Searle insists that a third-person description of our "behavioral, functional, neurobiological structures" does not capture our first-person conscious experience. So consciousness cannot be wholly "reduced." It has what Searle calls "a subjective or first-person ontology" that would be overlooked "if we redefine[d] consciousness in third-person, objective terms." Searle makes this claim for both human beings and other animals. For, though Searle does not say so, Darwin not only repatriated us to the animal kingdom, but thereby restored to animals the inwardness that they had been denied by Descartes.

Besides the mind-body problem, Searle instructively discusses intentionality, causality, free will, the unconscious, perception, personal identity, and the self. I can say only a few words about Searle's own answer to his central question of how minds fit into the rest of the universe.

He proposes that we "approach the relation of consciousness to brain processes naively, as if we did not have many centuries of ... confusion." He attributes this confusion to the fact that the traditional vocabulary for discussing the mind-body problem presupposes the mutual exclusion of the mental and the physical. To paraphrase the twentieth-century philosopher Ludwig Wittgenstein, a picture holds us captive: namely, the Cartesian picture of mind here over and against body there. And we cannot find our way out of this picture, since it lies in our language, and our language seems to repeat it to us at every turn. According to Searle, the very terms of the question of how matter could produce minds make this question impossible to answer. For the question presupposes that the mental and the physical are two different orders. Searle's strategy for escaping the "picture" introduced by the Cartesian categories of the mental and the physical is to try to bring mental phenomena "down to the level of real animal biology." To paraphrase Wittgenstein again, Searle's strategy may be put, Don't think, but look and see! From the biological point of view, it appears obvious to him that conscious thoughts and feelings "are caused by neurobiological processes in the brain; and they exist as biological features of the brain system," which is to say as "a system-level biological feature," "at a level higher than that of neurons and synapses." More simply put, "Consciousness is a biological feature of the brain [it should be added: suitably embodied] in the same way that digestion is a biological feature of the digestive tract." So Searle holds that consciousness is "causally reducible," even though it is not "ontologically reducible," a point that we may restate by saying that how consciousness works can be explained, in principle, in terms of points of mass/energy in fields of force, but consciousness cannot be understood in these terms. For to speak only of points of mass/energy, or for that matter of neurons and synapses, would be to explain consciousness away.

Searle calls his position "biological naturalism" and recommends it as avoiding both dualism and materialism. Further, against so-called mysterians like McGinn, Searle thinks that biological naturalism dispels the "mystery" of how there could ever be conscious minds in a material world. For Searle, the only reason why philosophers would find the existence of consciousness mysterious is that they have been captivated by the Cartesian picture, so that they just cannot fathom, as a matter of principle, how squishy gray matter in our heads should be able to give rise to rich mental lives. Searle counters that, as a matter of fact, "the world works in such a way that some biological processes are qualitative, subjective, and first-personal." Once we recognize this fact, and free our minds from the Cartesian categories, the mind-body problem simply falls away, to be succeeded by the more productive investigations of neurobiology.

But does Searle's biological naturalism really settle the philosophical question of "how the human reality relate[s] to the rest of reality"? I wonder whether Searle's philosophy of mind does not call for a renewed philosophy of nature. The question to consider is whether the fact that nature produces minds gives us reason to rethink our picture of nature--which is also a legacy of the seventeenth century--as essentially mindless, no more than extended bodies in space without any intrinsic inwardness. In other words, does the fact that nature has produced conscious life like us call into question, not the conviction that what is is matter, but the conception of matter as pure "extension"--lifeless, mindless stuff spread out in length, breadth, and depth, but without the least trace of the inwardness characteristic of our bodily lives? If so, we would have to rethink the rest of reality in the light of our own.

Bernard G. Prusak teaches humanities and political theory at Boston University.