Each man is a new power in Nature. He holds the keys of the world in his hands. No quality in Nature’s vast magazines he cannot touch, no truth he cannot see. Silent, passive, even sulkily Nature offers every morning her wealth to man. She is immensely rich; he is welcome to her entire goods, but she speaks no word, will not so much as beckon or cough; only this, she is careful to leave all her doors ajar . . . In her hundred-gated Thebes every chamber is a new door.