Robert E. Lana examines psychological theory from a historical and epistemological perspective. He presents a history of the major epistemological ideas that are either implicit or explicit in psychological theory. A review of psychological thought from the Greeks to the early behavorists includes the work of such thinkers as Descartes, Locke, Hume, Kant, and James. Machiavelli, Vico, and Nietzsche are presented as key figures who contributed the major ideational structures that paved the way for the Freudian revolution.

The dominant theme of the book is the constant epistemological