Sex.

Biology tells us that that life is all about sex. That may be so. Self split itself in two so not to be by itself. I am more inclined to believe it's not so much about sex per se but more about companionship. Companionship is one's purpose and sex is one's method. And yes. Of course there is no such thing as a split or division in truth. Self differentiation does not imply Self division. Self is at any time one not wanting to be alone and the purpose of self is to embrace itself.
~ Wald Wassermann