Gary Gutting is a philosopher at the University of Notre Dame who writes regularly for the “Opinionator” site of the New York Times. The pieces I’ve read have been religion-friendly, accommodationist, not very convincing, and devoted largely to bashing New Atheism on the usual flimsy grounds (e.g., see here, here and here). I’m not sure whether Gutting is religious, but he certainly despises atheism and shows a weakness for the numinous.
His piece in last Sunday’s Opinionator, “Mary and the zombies: Can science explain consciousness?” is in the latter vein, questioning whether consciousness can be explained by physical phenomena. He’s not touting a soul here, but mounting an attack on physicalism: the idea that, at bottom, there’s a physical explanation for all phenomena in the universe. In this case, the phenomenon that supposedly defies physical explanation is consciousness. (This, of course, is also an argument of many religious people.)
Gutting gives two examples that, he claims, raises serious questions about a physical explanation of consciousness. Both of these are well known to philosophers: “Mary’s room” and “the zombie hypothesis.”
I’ll present them both and then tender a few remarks. I am under no illusion that I know enough about philosophy to analyze them thoroughly, and though I’ve read books on consciousness, I’m certainly no expert. My comments are from the viewpoint of an interested evolutionary biologist.
First, Mary’s room:
First, consider Mary, a leading neuroscientist who specializes in color perception. Mary lives at a time in the future when the neuroscience of color is essentially complete, and so she knows all the physical facts about colors and their perception. Mary, however, has been totally color-blind from birth. (Here I deviate from the story’s standard form, in which—for obscure reasons—she’s been living in an entirely black-and-white environment.)
Fortunately, due to research Mary herself has done, there is an operation that gives her normal vision. When the bandages are removed, Mary looks around the room and sees a bouquet of red roses sent by her husband. At that moment, Mary for the first time experiences the color red and now knows what red looks like. Her experience, it seems clear, has taught her a fact about color that she did not know before. But before this she knew all the physical facts about color. Therefore, there is a fact about color that is not physical. Physical science cannot express all the facts about color.
What Gutting fails to mention here is that there have been many criticisms of the idea that Mary has learned a “fact about color” not conveyable by knowing “all the physical facts about color.” You can read a series of refutations in the Wikipedia article on “The knowledge argument,” most of them apparently arguing that Mary gains no new “facts” or “knowledge,” but experience. Others, like Dan Dennett, argue that that experience is knowledge that Mary would have acquired in advance if she knew everything neurological about color. I’m not capable of judging these, but since science has given us no evidence for anything that doesn’t comport with physicality, I’m loath to exempt consciousness from this generalization.
I see the experience of red as something that is still a deep puzzle to us, but one that could in principle be explained. We might, for example, some day build a computer that mimics our brain, and which will be able to convey to us its consciousness of color. Our brain is, after all, composed of atoms, and evolved from primordial molecules that certainly had no consciousness, much less a consciousness of color. Given the continuity of material phenomena inherent in evolution, I simply cannot see how subjective sensations, which arose some time during evolution, represent a non-materialistic reality. Gutting characterizes that reality thusly:
They [Frank Johnson and David Chalmers, who proposed the two scenarios] maintain that there is no world beyond the natural one in which we live. Their claim is rather that this world contains a natural reality (consciousness) that escapes the scope of physical explanation. Chalmers, in particular, supports a “naturalistic dualism” that proposes to supplement physical science by postulating entities with irreducibly subjective (phenomenal) properties that would allow us to give a natural explanation of consciousness. Not surprisingly, however, some philosophers have seen Jackson’s and Chalmers’s arguments as supporting a traditional dualism of a natural body and a supernatural soul.
Given that these entities evolved from nonconscious physical entities, I fail to see how they can be “irreducibly subjective,” that is, independent of or not explainable by material phenomena. Maybe this is logically possible, but given the history of scientific successes resting firmly on materialism, I doubt that “naturalistic dualism” (which seems an incoherent oxymoron) will be the case. And I certainly see no reason to abandon scientific studies of consciousness resting on analyses of our brain, studies of artificial intelligence, and so on.
Gutting’s second example involves zombies (highlights are mine):
Second, consider a zombie. Not the brain-eating undead of movies, but a philosophical zombie, defined as physically identical to you or me but utterly lacking in internal subjective experience. Imagine, for example, that in some alternative universe you have a twin, not just genetically identical but identical in every physical detail—made of all the same sorts of elementary particles arranged in exactly the same way. Isn’t it logically possible that this twin has no experiences?
It may, of course, be true that, in our world, the laws of nature require that certain objective physical structures be correlated with corresponding subjective experiences. But laws of nature are not logically necessary (if they were, we could discover them as we do laws of logic or mathematics, by pure thought, independent of empirical facts). So in an alternative universe, there could (logically) be a being physically identical to me but with no experiences: my zombie-twin.
But if a zombie-twin is logically possible, it follows that my experiences involve something beyond my physical makeup. For my zombie-twin shares my entire physical makeup, but does not share my experiences. This, however, means that physical science cannot express all the facts about my experiences.
I’m not sure I understand the conundrum here. My view is that a being physically identical to me would have the same neuronal configuration as me, and therefore the same stored memories, the same Coyne-ian consciousness, and the same subjective experiences. Whether or not the laws of nature are logically necessary—and some of them could be, resting on certain basic facts—seems irrelevant to this argument. So I’m not sure that using the word “logically possible” gives this argument any scientific force—indeed, I’m not sure what Gutting means by “logically” possible. Yes, the laws of nature could be different for the zombie than for me, producing different subjectivity, but that’s assuming what he’s trying to prove. Or so I conclude. Further, science gives us no evidence that the laws of nature would operate differently in a body identical to mine, except for the possibility that quantum phenomena could cause slight differences between the consciousness of me and my zombie. But even quantum phenomena are physical, not some kind of “irreducible subjective property.” Quantum phenomena are part of physicalism.
What Gutting seems to be floating here is a kind of “philosophy of the gaps” argument, resting not on scientific studies but on “logical possibilities”. It’s also logically possible that we were all created yesterday by aliens or gods, with all our memories and a bogus history implanted by our creators, but I don’t see the need to devote time to that. I’m concerned with scientific probabilities, not logical possibilities.
I am confident, as is Dennett, that one day consciousness will be explained by reductive physical analysis. It’s a hard problem, but many problems once thought insuperable have yielded to scientific study. For many years everyone believed in dualistic free will, but now we’re beginning to understand that our sense of “agency” is bogus, and that in fact our “free” choices may be largely or completely predicted from our genes and our environments, i.e., physical phenomena. Our feeling of agency is, of course, one aspect of our consciousness. This doesn’t explain the source of that feeling, but it’s entirely possible that agency is a confabulation installed in us by evolution to help make sense post facto of what we do, or relate our experiences to others.
At any rate, these are just some preliminary thoughts, and I’m prepared to accept that they’re naive, incomplete, or dead wrong. Gutting claims that he takes no stand on the irreducibility of consciousness, and solicited readers’ comments on his piece. I do the same here.
He’s promised a follow-up Opinionator on this topic this week, but I haven’t yet searched for it.