This work offers a "symposium" on the nature of human sexual difference drawing on Plato's masterpiece: having explored the observed phenomena of sexual difference, four stories are told of the origins, essence, and ends of the human male and female. First, the evolutionists, and then Simone de Beauvoir, and Judith Butler present their accounts. Next, a fourth (and unique vision for our age) is added: the thought of Thomas Aquinas is placed in dialogue with the evolutionists, Beauvoir, and Butler, thereby introducing into contemporary discourse a voice that is both ancient and new. The work seeks to trace each protagonist's account to its fonts, so providing a perspective from which various streams of thought might be understood both in their divergence and common origins. It thus hopes to offer a common language and an interpretive key in a realm where confusion and misunderstanding too often reign.