Never cite an author except in a matter of doubtful credit. — The Great Instauration

"Some, indeed, there have been who have gone more boldly to work and, taking it all for an open matter and giving their genius full play, have made a passage for themselves and their own opinions by pulling down and demolishing former ones; and yet all their stir has but little advanced the matter, since their aim has been not to extend philosophy and the arts in substance and value, but only to change doctrines and transfer the kingdom of opinions to themselves; whereby little has indeed been gained..."

"In the mathematics it is easy to follow the demonstration when you have a machine beside you, whereas without that help all appears involved and more subtle than it really is."

"Never introduce a controversy unless in a matter of great moment."

"For all that concerns ornaments of speech, similitudes, treasury of eloquence, and such like emptinesses let it be utterly dismissed."

"As soon... as a history has been completed of all these things which I have mentioned, namely Generations, Pretergenerations, Arts and Experiments, it seems that nothing will remain unprovided whereby the sense can be equipped for the information of the understanding. And then shall we be no longer kept dancing within little rings, like persons bewitched, but our range and circuit will be as wide as the compass of the world."

"These mediocrities and middle ways so much praised, in deferring to opinions and customs, turn to the great detriment of the sciences."