A more accurate diagnosis of Hitler's condition would be pseudologia phantastica, that form of hysteria which is characterized by a peculiar talent for believing one's own lies. For a short spell, such people usually meet with astounding success, and for that reason are socially dangerous. Nothing has such a convincing effect as a lie one invents and believes oneself, or an evil deed or intention whose righteousness one regards as self-evident. At any rate they carry far more conviction than the good man and the good deed, or even the wicked man and his purely wicked deed. Hitler's theatrical, obviously hysterical gestures struck all foreigners (with a few amazing exceptions) as purely ridiculous. When I saw him with my own eyes, he suggested a psychic scarecrow (with a broomstick for an outstretched arm) rather than a human being. It is also difficult to understand how his ranting speeches, delivered in shrill, grating, womanish tones, could have made such an impression. But the German people would never have been taken in and carried away so completely if this figure had not been a reflected image of the collective German hysteria. It is not without serious misgivings that one ventures to pin the label of "psychopathic inferiority" on to a whole nation, and yet, heaven knows, it is the only explanation which could in any way account for the effect this scarecrow had on the masses. A sorry lack of education, conceit that bordered on madness, a very mediocre intelligence, combined with the hysteric's cunning and the power fantasies of an adolescent, were written all over this demagogue's face.
Carl Gustav Jung, "After the Catastrophe", Essays on Contemporary Events, 1936-1946,
translated by R. F. C. Hull, Routledge, London, 2002, pp. 70-71