Abstract

Sigmund Freud (1856–1939) created a theory of psychology that has had a more profound influence on twentieth‐century thinking about human life and human culture than any other produced in this century. Freud presented his theory as the product of scientific work. He did not offer it as part of a philosophical system and did not advance philosophical arguments to defend it. Rather he based it on evidence he gathered from the observations he made as a physician specializing in nervous disorders, and he enlarged and modified it on the basis of further observations and reflections. Consequently, it is necessary first to explain how the theory developed and what its central ideas are before discussing its philosophical import.