Among the major theorists studying the effect of the external world on the individual, none had a more ambiguous relationship to the psychic manifestations of the environment than Wilfred Bion. On the one hand his theory of the mind contained a new concept, beta elements, to depict the intrusion of the material world into the mental sphere, while on the other he radically opposed the use of sensory perception as a source for clinical insight. The author examines this dichotomy as an outgrowth of her interest in the place of external reality in psychoanalytic theory. As a result, this essay is an attempt to clarify the source for Bion's theorizing, in order to be more specific about the applicability of his concepts and his precepts.