Drawing on the influential contributions of Wilfred Bion and Donald Meltzer to psychoanalysis, Bion and Meltzer’s Expeditions into Unmapped Mental Life explores and addresses the clinical implications of their work, both through revisiting several of their conceptions as well as illustrating them through detailed clinical material from the analyses of children, adolescents and adults. Psychoanalysis strives towards truth; this is its essence. However, emotional truth is often unknowable and not amenable to verbal communication. This ineffable mental realm is at the heart of both Bion and Meltzer’s psychoanalytic endeavours. Bion’s writings reflect a developmental stage in the evolution of psychoanalysis, extending clinical work to mental realms that were seemingly unreachable. Donald Meltzer further infuses Bion’s thinking with his own original notions of beauty and aesthetics, imbuing Bion’s profound thinking with a poetic and lyrical tenor. Writing in a clear and lucid manner, Avner Bergstein integrates Bion’s sometimes highly theoretical thinking with everyday clinical practice, to facilitate his dense and condensed formulations and make them clinically accessible and useful. Bion and Meltzer’s Expeditions into Unmapped Mental Lifee is written for psychoanalysts and psychoanalytically oriented psychotherapists who are attracted to Bion and Meltzer’s radical thinking.