Wilfred R. Bion is considered a ground-breaking psychoanalyst. His thinking is rooted in Freud and Klein from where it takes an original flight. Reading Bion shows the evolution of his seminal insights in psychic functioning and puts them in a wider context. Rudi Vermote integrates a chronological close reading and discussion of Bion’s texts, with a comprehensive approach of his major concepts. The book is divided in two main parts: Transformation in Knowledge: Bion’s odyssey to understand psychic processing or the mind Transformation in O: in which Bion reinterprets his former concepts from the dimension of the unknown and unknowable The running text is put against a background of biographical data and scientific, artistic and philosophical influences on his work, which are highlighted in boxes and separate chapters. Bion’s concepts are important for anyone dealing with the mind. His ideas have an ongoing deep impact on psychoanalysis, psychotherapy and psychopathology. His concepts help to understand psychic change, creativity, individual psychodynamics and small and large-group phenomena. The discovery of their value for studies on art, literature, sociology, religion, economics has just begun. Reading Bion starts from the very beginning so that it is instructive for people who are new to his work, but the close reading and background information make it a meaningful companion for experienced psychoanalysts and psychotherapists studying his work.