When I was a boy I used to think that things progressed by contrasts, that there was a law of contrasts. But this was building the world out of blocks. Afterwards I came to think of the energizing that comes from mere interplay, interaction. Thus, the various faculties of the mind co-exist and interact, and there is as much delight in this mere co-existence as man and woman find in each other's company . . . Cross reflections, modifications, counter-balances, complements, giving and taking are illimitable. They make things inter-dependent and their inter-dependence sustains them and gives them pleasure.

-- Wallace Stevens, 1940 Letter to Hi Simons