Deductive and inductive reasoning both played an essential part in Freud's construction of psychoanalysis. In this paper, the author explores the happy marriage of empiricism and rationalism in Freud's use of deductive reasoning in the construction of psychoanalytic theory. To do this, the author considers three major amendments Freud made to his theory: (i) infant and childhood sexuality, (ii) the structural theory, and (iii) the theory of signal anxiety. Ultimately, the author argues for, and presents Freud as a proponent of, the epistemological position that he calls critical realism.