Formerly the natural state of man was not what it is now, but quite different. For at first there were three sexes, not two as present, male and female, but also a third having both together… Next, the shape of man was quite round, back and ribs passing about it in a circle; and he had four arms and an equal number of legs, and two faces on a round neck, exactly alike; there was one head with these two opposite faces, and four ears, and two privy members, and the rest as you might imagine from this. And why were there were three sexes, and shaped like this, was because the male was at first born of the sun, and the female of the earth, and the common sex had something of the moon, which combines both male and female…
[…]After a deal of worry Zeus had a happy thought,…’I will slice each of them down through the middle!’ […]So when the original body was cut through, each half wanted the other, and hugged it; they threw their arms round each other, and hugged it; they threw their arms round each other desiring to grow together in the embrace, and died of starvation and general idleness because they would not do anything apart from each other. […]But Zeus pitied them and found another scheme; he moved their privy parts in front, for these also were outside before, and they had begotten and brought forth not with each other but with the ground, like the cicadas. […]So you see how ancient is the mutual love implanted in mankind, bringing together the parts of the original body, and trying to make one out of two, and to heal the natural structure of man.
–Plato, Symposium
Chapin City Blues 