Questions about learning and discovery have fascinated philosophers from Plato onwards. Does the mind bring innate resources of its own to the process of learning or does it rely wholly upon experience? Plato was the first philosopher to give an innatist response to this question and in doing so was to provoke the other major philosophers of ancient Greece to give their own rival explanations of learning. This book examines these theories of learning in relation to each other. It presents an entirely different interpretation of the theory of recollection which also changes the way we understand the development of ancient philosophy after Plato. The final section of the book compares ancient theories of learning with the seventeenth-century debate about innate ideas, and finds that the relation between the two periods is far more interesting and complete than is usually supposed.