Collective psychopathology stands as one of the most diagnostically ambitious concepts in the depth-psychology corpus, designating the capacity of entire peoples, nations, and historical epochs to manifest pathological psychological states analogous — or literally homologous — to those observed in individual clinical cases. Jung is the primary architect of this diagnosis: across Civilization in Transition, The Undiscovered Self, and the Two Essays, he insists that political mass movements, nationalist frenzy, and totalitarian violence are not merely political aberrations but clinical phenomena — ‘psychic epidemics,’ ‘mass psychoses,’ and instances of ‘collective possession’ arising when unconscious contents overwhelm the ego’s regulatory function. The argument pivots on his contention that latent psychopathology is far more widespread than clinical statistics reveal, and that when affective temperature in a group exceeds a critical threshold, reason yields to slogan and wish-fantasy, placing the latently disturbed in a position of catastrophic social influence. Erich Neumann, in Depth Psychology and a New Ethic, extends the analysis by tracing collective pathology to the ethics of repression and shadow-projection endemic to Western moral systems. Von Franz identifies weak ego-development as the psychological vector through which individuals become susceptible to collective absolutistic movements. The concept thus joins individual psychology, cultural critique, and political diagnosis into a single theoretical arc, raising urgent and still unresolved questions about responsibility, moral maturation, and the possibilities of collective redemption.