“While he was engaged in this self-analytic activity, he continued to develop his theoretical work. At the Munich Psycho-Analytical Congress in September 1913, he spoke on psychological types. He argued that there were two basic movements of the libido: extraversion, in which the subject’s interest was oriented toward the outer world, and introversion, in which the subject’s interest was directed inward. Following from this, he posited two types of people, characterized by a predominance of one of these tendencies. The psychologies of Freud and Adler were examples of the fact that psychologies often took what was true of their type as generally valid. Hence what was required was a psychology that did justice to both of these types.”