Meaning of primitive -- Materials for a psychology of primitive man -- Quest for unity: the principle of unification -- Organic basis of unification -- Instinct and intelligence -- Primitive reflection upon instinct -- Generalized mind -- Theory of M.Levy-Bruhl -- Formation of primitive concepts -- Primitive concepts and primitive religion -- Reasoning of primitive man -- Integration of custom -- Disintegration of custom and the tribe -- Higher unifications -- Unification and happiness