Evolutionary psychology was the organizing framework—the source of explanatory adequacy or a theory of the computation —that the science of psychology had been missing. Like vision and language, our emotions and cognitive faculties are complex, useful, and nonrandomly organized, which means that they must be a product of the only physical process capable of generating complex, useful, nonrandom organization, namely, natural selection. An appeal to evolution was already implicit in the metatheoretical directives of Marr and Chomsky, with their appeal to the function of a mental faculty, and evolutionary psychology simply shows how to apply that logic to the rest of the mind.

Steven Pinker, "Foreword" in: Buss, David M., ed. The handbook of evolutionary psychology. John Wiley & Sons, 2005. p. xiv