Considering that introductory books cannot replace an author's original words, and that Bion's concepts are often found to be difficult to grasp, Dr Paulo Sandler has compiled an unusual style of dictionary. He assembles relevant quotations from Bion's texts together with the meaning of concepts and their place in the history of their development.Dr Sandler aims to present Bion's work as it is, rather than to convey his own opinions, although he does include his own insightful comments between entries in order to clarify certain issues. This well-organized dictionary will be a valuable tool in deepening the apprehension of Bion's compacted style of writing.