Over the previous decade, Robert E. Lana had attempted to understand the enterprise of psychology as a totality. Such an attempt was unpopular in the 1930s, 1940s and 1950s but had become increasingly more popular to psychologists in the 1970s. After considerable study, he became convinced that the twin vehicles for such a task were the history of the field and the epistemological contexts into which psychological theories fit. Originally published in 1976, the initial chapters in this volume are devoted to explaining, through history, the major epistemological ideas either implicit or explicit in modern psychological theory. Later chapters are studies of the epistemological contexts that, in part, yield modern psychological theory.