Pictures, propagated by motion along the fibers of the optic nerves in the brain, are the cause of vision.
My Design in this Book is not to explain the Properties of Light by Hypotheses, but to propose and prove them by Reason and Experiments: In order to which, I shall premise the following Definitions and Axioms.
Nature is pleased with simplicity. And nature is no dummy.
If I am anything, which I highly doubt, I have made myself so by hard work.
I can measure the motion of bodies but I cannot measure human folly.
If the ancient churches, in debating and deciding the greatest mysteries of religion, knew nothing of these two texts, I understand not why we should be so fond of them now the debate is over.