The demonic personality occupies a distinctive and precise position within John Beebe’s eight-function, eight-archetype model of psychological type — one of the most systematically developed contributions to post-Jungian typology. Beebe introduced the term to designate the archetypal role carried by the eighth function-attitude, the shadow counterpart of the inferior (fourth) function. Where the opposing personality shadows the superior function, the demonic personality operates at the greatest remove from ego-consciousness, mobilising the least differentiated function in its most destructive, undermining register. It distorts meaning, dismantles insight, and subverts the personality’s integrative aims — though Beebe insists it may also, on rare occasions, deliver unexpected illumination. The term draws on the ancient Greek daimon tradition, and Beebe employs the spelling ‘daimonic’ interchangeably with ‘demonic’ to honour that ambivalence. James Hillman, approaching the concept from a different angle via the acorn theory and his reading of Hitler’s daimon, identifies a related pathology: the daimonic becomes destructive precisely when the personality’s relation to its inner calling is dysfunctional, producing megalomania rather than vocation. The tension between Beebe’s structural-typological account and Hillman’s mythopoeic-characterological account defines the central interpretive fault line in the corpus around this term.