Sir Isaac Newton was asked how he discovered the law of gravity. He replied, "By thinking about it all the time.

If I have ever made any valuable discoveries, it has been due more to patient attention, than to any other talent

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.

This principle of nature being very remote from the conceptions of Philosophers, I forbore to describe it in that book, least I should be accounted an extravagant freak and so prejudice my Readers against all those things which were the main designe of the book.

We are to admit no more causes of natural things than such as are both true and sufficient to explain their appearances.

Truth is the offspring of silence and meditation.

What Descartes did was a good step. You have added much several ways, and especially in taking the colours of thin plates into philosophical consideration. If I have seen a little further it is by standing on the shoulders of Giants.