This paper presents evidence that Bion's epistemological contributions drew on the work of R. B. Braithwaite, a British philosopher of science, more than has generally been acknowledged. Braithwaite introduced the "scientific deductive system", a term Bion adopted. It proposed that empirical scientific methods could be applied to immaterial subjects of study, including "unconscious mental processes" (Braithwaite 1953, ix). Bion's private work journal, collected in Cogitations, documents Braithwaite's direct influence throughout its entries, particularly in one dated 10 January 1959, entitled "Scientific method" (Bion 1959b). This paper reviews relevant elements of Braithwaite's work, and examines Bion's "Scientific method" and samples from his epistemological work to argue that one of Bion's goals was to bring an empirically based scientific model to psychoanalytic theory and clinical practice. More than a matter of academic interest, Braithwaite's work lends pragmatically useful context to understand Bion's theoretical and clinical intentions in greater depth. It also suggests the main reasons why his project did not come fully to fruition, which led Bion to turn from the scientific deductive system towards his later developments.
Keywords: Bion; Braithwaite; clinical method; history of psychoanalysis; observation; scientific deductive system.