ABSTRACT
Dividing Wilfred R. Bion's work into four periods makes it easier to situate and understand his concepts and their elaboration by others. The major caesura in Bion's work is between period 2 and 3, when a shift takes place from looking at mental phenomena from the perspective of transformations in knowledge, to an approach in terms of transformations in O. The Northfield experiment was the cradle of Bion's ideas on groups. Foulkes, Pines and Main continued in a more therapeutic way, so that Northfield became the origin of therapeutic communities all over the world. The aim of psychoanalysis became for Grotstein the development of the infinite in finite man. Bion switches from pure emotional experience in the transcendental period to a more philosophical not-knowing, although this is fully in line with the transcendental period. Ultimately he transformed them to a more philosophical Socratic stance of fundamental not-knowing in thinking about psychoanalysis in his lectures and supervisions of the last period.
