The primeval man was round, his back and sides forming a circle; and he had four hands and four feet, one head with two faces, looking opposite ways, set on a round neck and precisely alike; also four ears, two privy members, and the remainder to correspond… Terrible was their might and strength, and the thoughts of their hearts were great, and they made an attack upon the gods… The gods could not suffer their insolence to be unrestrained… At last, after a good deal of reflection, Zeus discovered a way. He said: "Methinks I have a plan which will humble their pride and improve their manners; men shall continue to exist, but I will cut them in two and then they will be diminished in strength and increased in numbers; this will have the advantage of making them more profitable to us. They shall walk upright on two legs, and if they continue insolent and will not be quiet, I will split them again and they shall hop about on a single leg." He spoke and cut men in two, like a sorb-apple which is halved for pickling… Each of us when separated, having one side only, like a flat fish, is but the indenture of a man, and he is always looking for his other half… And when one of them meets with his other half, the actual half of himself, the pair are lost in an amazement of love and friendship and intimacy.
(Plato, around 380 BC)