Extreme or rare statements reveal latent potential within supposedly normal phenomena.

Evidence

Rare or even unique statements may be elucidated by the discussion. Such statements, often of an extreme nature, may throw considerable light on potentialities which lie within supposedly `normal’ areas, just as illness helps us to understand health. At the same time, attention to the consistency of the interpretation of these statements with the over-all picture provides a safeguard against arbitrariness. A subjective or what might be called speculative element has a place in this method, just as it does in psychoanalysis, from which many of our categories have been drawn. — Rolf Wiggershaus, The Frankfurt School, 1783

Categorization

• XREF: The extreme-as-diagnostic principle echoes the methodological stance behind reading liminal or deviant cases to understand the norm — parallels Foucault’s use of asylums and prisons to define the normal.