I am ashamed to tell you to how many figures I carried these calculations [of Pi], having no other business at the time

The main Business of Natural Philosophy is to argue from Phænomena without feigning Hypotheses, and to deduce Causes 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 to such like Questions.

To arrive at the simplest truth requires years of contemplation.

Whence arises all that order and beauty we see in the world?

He who thinks half-heartedly will not believe in God; but he who really thinks has to believe in God.

If you are affronted it is better to pass it by in silence, or with a jest, though with some dishonor, than to endeavor revenge. If you can keep reason above passion, that and watchfulness will be your best defenders.

You ask me how, with so much study, I manage to retene my health. Morpheus is my last companion; without 8 or 9 hours of him yr correspondent is not worth one scavenger's peruke. My practices did at ye first hurt my stomach, but now I eat heartily enou' as y' will see when I come down beside you.