The significance of a fact is relative to [the general body of scientific] knowledge. To say that a fact is significant in science, is to say that it helps to establish or refute some general law; for science, though it starts from observation of the particular, is not concerned essentially with the particular, but with the general. A fact, in science, is not a mere fact, but an instance. In this the scientist differs from the artist, who, if he deigns to notice facts at all, is likely to notice them in all their particularity.

We must be skeptical even of our skepticism.

Literature is inexhaustible, with every book a homage to infinity

If you question any candid person who is no longer young, he is very likely to tell you that, having tasted life in this world, he has no wish to begin again as a "new boy" in another.

Admit at least one painful truth to yourself every day. Teach yourself to feel that life would still be worth living even if you were not immeasurably superior to all your friends. Exercises of this sort, prolonged through several years, will at last enable you to admit facts without flinching, and will, in so doing, free you from the empire of fear over a very large field.

When you want to teach children to think, you begin by treating them seriously when they are little, giving them responsibilities, talking to them candidly, providing privacy and solitude for them, and making them readers and thinkers of significant thoughts from the beginning. That’s if you want to teach them to think.

Have no respect for the authority of others, for there are always contrary authorities to be found