Clark starts out with a simple evolutionary theme: the organism most likely to succeed is the one best equipped to deal with its environment. He argues that this is the fundamental issue of intelligence. What should be studied is what mechanisms have been developed for this purpose, how they were developed and why. Later he contrasts this to more traditional views of cognitive science which focus exclusively on what the mind does.

In the rest of the chapter Clark looks at some of the ways in which evolution takes place. In so doing, he develops two important principles. The first is what Clark calls the 007 principle which states that organisms will only store and process enough information to get the job done and no more — thus meeting the dual goals of economy and effectiveness. Contrast this with the direction of today’s "information age." The second principle states that the evolution of a complex whole will generally depend on its being built out of a combination of simpler parts, each of which has itself evolved as a whole stable unit. This applies to the neural modules we were born with and the evolution of knowledge in an individual brain. These two principles are extraordinarily important in determining and understanding the structures that the brain developed to process information.