Using the “War Journal” (June 1917-January 1919) of Bion and the “Commentaries” he wrote 50 years later, the author establishes links between the war experience of the adolescent Bion and certain concepts created by the analyst Bion. Most notably, those of “catastrophic change”, “nameless terror”, “psychotic personality”, and “group mentality”.

Key-words
Catastrophic change, Group mentality, Nameless terror, Psychotic personality, Learning through experience.