It's not what we eat but what we digest that makes us strong; not what we gain but what we save that makes us rich; not what we read but what we remember that makes us learned; and not what we profess but what we practice that gives us integrity.
They are the best physicians, who being great in learning most incline to the traditions of experience, or being distinguished in practice do not reflect the methods and generalities of art.
Again men have been kept back as by a kind of enchantment from progress in science by reverence for antiquity, by the authority of men counted great in philosophy, and then by general consent.
There are and can be only two ways of searching into and discovering truth. The one flies from the senses and particulars to the most general axioms, and from these principles, the truth of which it takes for settled and immovable, proceeds to judgment and to the discovery of middle axioms. And this way is now in fashion. The other derives axioms from the senses and particulars, rising by a gradual and unbroken ascent, so that it arrives at the most general axioms last of all. This is the true way, but as yet untried.
Another error is an impatience of doubt and haste to assertion without due and mature suspension of judgment. For the two ways of contemplation are not unlike the two ways of action commonly spoken of by the ancients; the one plain and smooth in the beginning, and in the end impassable; the other rough and troublesome in the entrance, but after a while fair and even. So it is in contemplation; if a man will begin with certainties, he shall end in doubts; but if he will be content to begin with doubts, he shall end in certainties.
The images of mens wits and knowledge remain in books. They generate still, and cast their seeds in the minds of others, provoking and causing infinite actions and opinions in succeeding ages