Dreaming Souls: Sleep, Dreams and the Evolution of the Conscious Mind (Philosophy of Mind Series)

It is a long-held notion of evolutionary theory that every aspect of behavior has an adaptive purpose, making the organism that exhibits it more fit for survival. That view hits a wall when it is brought to bear on dreaming, an act that seems to have no discernible adaptive advantage.

What good does it do us to dream? Cognitive scientist Owen Flanagan addresses this and related questions in Dreaming Souls, an endlessly interesting excursion into the philosophy of mind. He proposes, first, that dreaming is simply a by-product of the ordinary awareness that allows us to live as conscious beings, an unintended rejoinder to our waking states. Nature selected mammals to have rigid skeletons in a calcium-rich environment, Flanagan notes, but "cared not one bit about their color"; in the same way, he suggests, dreaming may simply be "an expectable side effect of selection for creatures designed to have and utilize experiences while they are awake, and which continue to have experiences after the lights go off." All this is not to say that dreams are unimportant, Flanagan adds, even though they may not be especially trustworthy; dreams may be a useful means of mind reading, something we constantly do while we are awake, interrogating ourselves constantly in order to gauge our thoughts and responses to the world around us. Dreams enable us, too, to mine below the narrative self of daily life, the person we present to others, a mask that may be quite different from who we really are. ("The self," Flanagan observes, "trades in fiction rather than fact.")

Flanagan proposes no definitive answers to the question of why we dream, but his ideas are stimulating and well-argued, and they open the door to further investigation. --Gregory McNamee