The aim of this chapter is to identify the origins of Bion’s concepts of psychoanalytic intuition, and of “O” (the ultimate Reality) in the building blocks of the metaphysics and process philosophy of Henri Bergson and Alfred North Whitehead. I will present documental evidence of Bion’s readings of Bergson and Whitehead, and conceptual evidence of their convergence of notions. The documental evidence was kindly provided by Francesca Bion, by means of photocopies of pages from two books from Bion’s library: Bergson’s (1896 [1911]) Matter and Memory, and Whitehead’s (1911) An Introduction to Mathematics, in which there were sentences underlined in pencil on several pages. Although he did not use these references explicitly, some of the central notions presented in Bergson’s Matter and Memory and Whitehead’s An Introduction to Mathematics are implicitly present in all of Bion’s work, starting from his 1948 paper “Psychiatry at a time of crisis”, followed by his papers from “Experiences in Groups” (1948-1952 [1961]), and throughout his psychoanalytic works (from 1962 to 1970).