As is well known, Sigmund Freud developed a conception of the human mind that included the Id or emotional/impassioned self, the Ego or rational/realistic self, and the Super-Ego or moral/conscientious self, and we can readily see in the first two of these a connection with the Dionysian and Apollonian spirits. Freud, in fact, originally posited only a bipartite division of the psyche: the Id and the Ego,¹⁷ and his scheme thus reflects a general intellectual tendency of the time. To understand this tendency, no book is more valuable then C. G. Jung's survey of the subject, Psychological Types,¹⁸ in which Jung looks at many different attempts to distinguish what we have called personality types. It is noteworthy, though perhaps not surprising, that these many attempts are all strictly dualistic. The table below summarizes Jung's survey.