This book is concerned chiefly with theories about learning in the history of philosophy, especially ancient philosophy. One of the main questions is: does our knowledge arise just out of experience or do we have some innate knowledge as well? The book is original in comparing different theories over a wide period in a way that should be accessible to students of philosophy and classics as well as professionals. It also has a section on seventeenth-century discussions of innate knowledge and their relation to ancient thought.