The Magic of Consciousness
Princeton University Press, $24.95, 256 pp.
When I discuss the scientific study of human consciousness with my general-education students, I begin by introducing them to a field-monitoring device used by a colleague in Environmental Studies. It stands three feet high and continually records temperature, relative humidity, precipitation, barometric pressure, wind speed and direction, and sun intensity. I ask my students, when it’s raining, does this device know it’s raining? Quickly they recognize that it doesn’t. So, I continue, how could you modify it so that it does know when it’s raining? Not just modify it so that it responds, zombie-like, to the rain—by putting on a hat, say—but so that it is conscious of the rain?
For this question they have no answer, and with good reason. This is known in consciousness studies as “the hard problem.” How can matter be put together in such a way that it can become conscious of the world? Philosophers have long asked this question, and in recent years it has been undertaken by biologists as well. The biologists fall into the materialist camp—those who believe, as the evolutionary psychologist Nicholas Humphrey does, that “nothing interesting occurs without a material cause.” Some philosophers are in the materialist camp with them, but others are dualists, who believe that mind and brain are not the same thing and that no material explanation of mind is possible. Still others are mysterians, who...