Plato’s Symposium contains some myths treating matters of gender and erotics, among them Aristophanes’ tale of the three primordial sexes of mankind. The text interprets the role of this myth both within the context of the Symposium and in modern science and expounds how the concepts of the third sex and androgyny have been re-actualized by sexology and psychoanalysis since the 19th century. The similarities with the ancient positions demonstrate the pertinence and power of
the myths’ overall propositions. The differences seem to imply the effective presence of other myths of Judaeo-Christian origin. In any case, the ancient tensions between an Aristophanic and a Socratic attitude are still active. Along these lines, the conceptual relations of androgyny or the third sex with erotic preferences are clarified.