The authors describe their attempt to review the evolution of psychoanalytic theory from a historical perspective, beginning with Freud's early manuscripts such as Studies on Hysteria. The Studies were approached from the following frames of reference: 1, the data of observation; 2, clinical interpretations; 3, clinical generalizations; 4, clinical theory; 5, metapsychology; 6, the author's philosophy. The data of observation were considered 'low-level' statements; clinical interpretations and generalizations middle levels of abstraction; clinical theories and metapsychological propositions the highest level of abstraction.

An attempt is made to trace the inductive and deductive reasoning that Breuer and Freud employed in their book. Comparisons are made between the more deductive, speculative thinking of Breuer and the more careful inductive reasoning of Freud, based primarily on conclusions empirically derived from clinical case material. The method used by the authors may be of value in further elucidation and validation of psychoanalytic constructs.