If youre good at finding the one right answer to lifes multiple-choice questions, youre smart. But intelligence is what you need when contemplating the leftovers in the refrigerator, trying to figure out what might go with them; or if youre trying to speak a sentence that youve never spoken before. As Jean Piaget said, intelligence is what you use when you dont know what to do, when all the standard answers are inadequate. This book tries to fathom how our inner life evolves from one topic to another, as we create and reject alternatives. Ever since Darwin, weve known that elegant things can 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 speciesexcept that the brain can turn the Darwinian crank a lot faster, on the time scale of thought and action. 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.