The human understanding is no dry light, but receives an infusion from the will and affections... What a man had rather were true he more readily believes.

Let every student of nature take this as his rule, that whatever the mind seizes upon with particular satisfaction is to be held in suspicion.

I use all sorts of things to work with: old brooms, old sweaters, and all kinds of peculiar tools and materials... I paint to excite myself, and make something for myself.

Discretion of speech is more than eloquence, and to speak agreeably to him with whom we deal is more than to speak in good words, or in good order.

...those experiments be not only esteemed which have an immediate and present use, but those principally which are of most universal consequence for invention of other experiments, and those which give more light to the invention of causes; for the invention of the mariner's needle, which giveth the direction, is of no less benefit for navigation than the invention of the sails, which give the motion.

Of all virtues and dignities of the mind, goodness is the greatest, being the character of the Deity; and without it, man is a busy, mischievous, wretched thing.

Look to make your course regular, that men may know beforehand what they may expect.