Consciousness used to be the crazy aunt in psychology's attic. Behaviorists and cognitive scientists alike practiced denial, but the squeaking floorboards troubled our dreams of a truly scientific discipline. Now, the old lady has been given pride of place in the parlor, with all the respectable scientific furnishing of societies and journals. But let's face it—she's still weird.
In some ways, the scientific study of consciousness has been a great success. We know more than ever about the relationship between specific types of conscious experiences and specific mind and brain states. Discouragingly, though, we are still no closer to solving the Problem of Big-C Consciousness. How is consciousness possible at all? How could the few pounds of gray goo in my skull give rise to my experience of the particular blue tint of the sky? Scientists and philosophers have suggested everything from quantum effects to information integration to brain-wave patterns. Some deny that consciousness exists at all; others argue that consciousness couldn't possibly be the result of just the brain. The scientific organizers of one of the principal consciousness conferences, in fact, deliberately let in woo-woo stuff about altered states and past lives on the principle that we have no idea where the answer might come from.
This may be less dispiriting when you realize we've been here before. The philosopher Patricia Churchland has pointed out that the problem of "Life" in the 19th century was much like the problem of "Consciousness" in the 21st. How could a few molecules ever give rise to breathing, moving, living creatures? The answer turned out to be that it was the wrong question. We now understand a great deal about the many different ways in which complex organisms with a multitude of different properties arise from much simpler chemistry. The Problem of Big-L Life has simply faded away.
Antonio Damasio is a neuroscientist who has done illuminating research on emotion, decision-making, and our perception of our own bodies. He was also one of the brave early researchers who tackled the problem of consciousness head-on, and he was rewarded by several successful popular books. Unfortunately, in Self Comes to Mind, Damasio seems to have jumped the shark. The book doesn't include either the new scientific research of the last 10 years or new philosophical clarity—although the style is readable, if a bit high-flown, it's often hard to make out the arguments. Instead, the book is a rather wandering and digressive restatement, with some minor variations, of Damasio's earlier views on consciousness.
Scientists should always think that what they study is the most interesting thing in the universe—why study it otherwise?—and Damasio believes that the key to consciousness lies, no surprise, in emotion, decision-making, and our perception of our own bodies. (Full disclosure: I am equally convinced that everything interesting can be explained by studying 3-year-olds.) He argues that the secret of capital-C Consciousness lies in the fact that brains are part of bodies. For Damasio, the neural process that tells us that our nose itches is at the root of even the most refined and ethereal spiritual experience. The body is the foundation of big-C Consciousness and provides the evolutionary bridge from even a primordial one-celled creature enveloping a speck of food to Damasio himself listening to Bach as he contemplates the Pacific Ocean.
The trouble with Damasio's hypothesis, as with all the hypotheses about capital-C Consciousness, is figuring out how you could test it. There is only one organism that I'm sure is conscious (namely, me), and there are only a few more organisms that tell me they are also conscious (namely, my fellow humans), though I'm pretty sure that my other fellow animals are conscious, too. Just to make things worse, the more you think about it, the less sure you are about the nature of your own consciousness, let alone that of other organisms. The philosopher Eric Schwitzgebel has collected many examples that shake your belief that you always know about your own experiences. For example, were you conscious a moment ago of the feeling of your feet in your shoes? You are now, of course, but were you before I made you think about it?
My fellow humans and I are (probably) conscious, and we do have bodily perceptions, emotions, decision-making capacities, and a sense of self, to be sure, but we also have all sorts of other abilities, capacities for complex visual perception, learning, attention, reasoning, etc., etc. Hardly any of those features can be independently manipulated. I can't rip my brain out of my body and see whether it experiences anything or genetically engineer a creature that had a mind but no body and examine its phenomenology. When consciousness shuts down altogether, as in sleep or coma, all of these other abilities shut down, too.