Daniel C. Dennett
Little, Brown & Co: Boston, 1991.
511 pp., $14.95 (paperback).
“CONSCIOUSNESS EXPLAINED" resounds with a sensationalistic, promising ring, something like "The Pyramids Deciphered" or "Madonna Unveiled." The latter subject has, of course, generously made such detective work unnecessary, but "consciousness" has never so obliged. Can the mind's eye see itself?
Several popular efforts over the last two decades, beginning with Fritjof Capra's The Tao of Physics, have informed readers that Buddhist appreciation of nonduality and the insubstantiality of the self are intriguingly echoed by modern physics. Quantum mechanics, the current best approximation to a scientifically reductionistic "theory of everything," clearly finds subject inextricably bound with object in every observation; rejects the isolated unconditioned existence of any particle; experimentally validates counterintuitive, enduring connections between particles previously associated but now distant; and knowingly uses simplifying approximations in its equations, for what otherwise would properly include the entire universe.
Of late, corresponding to this "deconstruction of the material world," the cognitive sciences (cognitive psychology, neuropsychology, brainmodeling computer science, etc.) have been able to offer some "deconstruction of the self." Philosophers have been attracted to this arena, in new attempts to shed light on the "mind-brain" dilemma, the knottiest of philosophical problems. "Mind" and "brain" have appeared quite unlike each other, yet with each apparently routinely able to influence (or mirror) the other—how then could such dissimilar substances so interact? Rene Descartes reasoned that the brain's strategically placed pineal gland accomplished this magical transmutation, but few today find such attempts at explanation more than amusing.
Enter Daniel Dennett, an heir of Wtttgenstein's philosophical vision. Dennett builds upon his own earlier theories in this volume, thoughtfully sampling intriguing results from recent experiments in cognition. Dennett is nothing if not persuasive, and offers an enjoyable read of this complex material. He is a clear, disciplined thinker, and his chapters are carefully crafted both in themselves and in their sequence. His arguments are spun out very gradually, building richly on detailed thought experiments, and with many color ful coinages to aid thought and memory (e.g., Cartesian Theater, Multiple Drafts Model, Orwellian and Stalinesque Revisions, the J oycean Machine, and so on). He succeeds in being memorable, as well as entertaining.
Dennett's chief target is our usually automatic view of ourselves as a sort of "ghost in a machine" when we are self-reflective. Even if we purportedly reject this dualistic notion, Dennett rightly asserts that it lingers in our notion of some unitary enduring "Central Meaner" in our head. This is the "self" who observes what is going on and serves as a seat of agency and intention, seeming to comprise a substratum on which consciousness is played out in one continuous stream. Dennett labels this idea "The Cartesian Theater." He urges we instead accept his "Multiple Drafts" model of consciousness, stressing decentralized agents who keep "editing" information in a parallel-processing brain, producing a "virtual" experience of a single continuous stream of consciousness that is actually but a poor illusion of its more complex functioning.
This is indeed an improvement, and is more consistent with brain functioning, although Dennett is extraordinarily vague about how his multiple agents and drafts are organized, interact, and can appear as one stream; and at times it appears that they could even comprise multiple Cartesian Theaters themselves. To his credit, Dennett explicitly acknowledges that he has merely exchanged one set of metaphors for another set, which currently seem to be less misleading.
Not above committing sloppy errors, Dennett misidentifies the Doppler effect, states that dogs and cats don't have color vision, and most jarring to me, appears not to know the distance from the pitcher's mound to home plate. Although such mistakes do not usually compromise his important arguments, they add a sense of carelessness to a background of carefully developed logic. More seriously, I cannot accept his functionalistic approach to dispensing with "qualia," those experienced "intrinsic qualities" (e.g. what seeing "red" feels like). Denying that such ineffable experiences represent "real" content or properties, he approaches a behaviorist account and equates consciousness with any device capable of making certain perceptual distinctions. Although this approach has a thoughtful, agnostic, and deconstructive tenor, it merely papers over the issue of how we are to consider our "inner experiential life."
The strengths of this work include the author's willingness to boldly tackle the central riddle of the mind-body problem (though the title Consciousness Explained claims far too much for this explication, illuminating as it is). He is not only clear in his writing (an achievement not all philosophers have attained) and willing to explore many perspectives from many disciplines with recent references, but also notably includes a thoughtful exploration of motivations for resisting his conclusions. And then thoughtfully concludes:
All I have done really, is to replace one family of metaphors and images with another. . . but. . . metaphors are the tools of thought. No one can think of consciousness without them, so it is important to equip yourself with the best set of tools available.
An immodest title but a more modest conclusion. There is little real disappointment, as this is a good read by a stimulating thinker.
William Greenberg is chief psychiatrist at Bergen Pines County Hospital in Bergen, New Jersey.