Sir Isaac Newton...on the first cause

The main business of natural philosophy is to argue from phenomena without feigning hypotheses, and to deduce cause from effects, till we come to the very first cause, which certainly is not mechanical; and not only to unfold the mechanism of the world, but chiefly to resolve these and such like questions: What is there in places almost empty of matter, and whence is it that the sun and the planets gravitate toward one another, without dense matter between them? Whence is it that nature doth nothing in vain, and whence arises all that order and beauty which we see in the world?

- Optiks, 1704