Includes bibliographical references (p. 165-166) and index

This book tries to fathom how our inner life evolves from one second to the next, as we steer ourselves from one topic to another, as we create and reject alternatives. It's not just a little person inside the head doing all this, though it's natural to assume that anything fancy requires an even fancier designer. Ever since Darwin, however, we've known that elegant things can also emerge (indeed, self-organize) from "simpler" beginnings. And, says theoretical

neurophysiologist William H. Calvin, the bootstrapping of new ideas works much like the immune response or the evolution of a new animal species - except that the brain can turn the darwinian crank a lot faster, on the time scale of thought and action. Few proposals achieve a perfect ten when judged against our memories, but we can subconsciously try out variations, using many brain regions. Eventually, as quality improves, we become conscious of our new invention

Drawing on anthropology, evolutionary biology, linguistics, and the neurosciences, Calvin also considers how a more intelligent brain developed using slow biological improvements over the last few million years. Long ago, evolving jack-of-all-trades versatility was encouraged by abrupt climate changes. Now, evolving intelligence uses a nonbiological track: augmenting human intelligence and building intelligent machines. In his concluding chapter, Calvin cautions about

arms races in intelligence. Just as the Red Queen explained to Alice in Wonderland, you might have to keep running to stay in the same place