What is it about human nature that makes our species capable of thinking scientifically? Inspired by a debate between Noam Chomsky and Jean Piaget, Scott Atran traces the development of natural history from Aristotle to Darwin, and demonstrates how the science of plants and animals has emerged from the common conceptions of folkbiology. The author proceeds not only from the more traditional philosophical, historical or sociological perspectives, but from a point of view he considers more basic and necessary to all of that of cognition.