AbstractThis text attempts to make an approach to the definition of psychosis from a review of the work of Wilfred Bion. To achieve this, it is necessary to cover some concepts like Ego, and some defense mechanisms such as splitting and projective identification. Relevant conceptualizations will be presented, to be integrated into the theory of thought in order to arrive at a definition of psychosis in Bion's ideas. Also, defined elements and their integration will be illustrated through vignettes of selected clinical cases for this purpose. Finally, we will corroborate the relevance of Bion's theory in contemporary clinic.Keywords: Psychosis, psychotic thinking, projective identification, splitting and Wilfred Bion
