Falsehood flies, and truth comes limping after it, so that when men come to be undeceived, it is too late . . . like a physician, who hath found out an infallible medicine, after the patient is dead.

—Jonathan Swift, The Examiner No. XIV (1710)

The most savage controversies are those about matters as to which there is no good evidence either way. Persecution is used in theology, not in arithmetic, because in arithmetic there is knowledge, but in theology there is only opinion.

—Bertrand Russell, “An Outline of Intellectual Rubbish” in Unpopular Essays, 1950

Pierre smiled, Natasha began to laugh, but Nicholas knitted his brows still more and began proving to Pierre that there was no prospect of any great change and that all the danger he spoke of existed only in his imagination. Pierre maintained the contrary, and as his mental faculties were greater and more resourceful, Nicholas felt himself cornered. This made him still angrier, for he was fully convinced, not by reasoning but by something within him stronger than reason, of the justice of his opinion.

—from Leo Tolstoy, War and Peace

I believe I have omitted mentioning that, in my first voyage from Boston, being becalm’d off Block Island, our people set about catching cod, and hauled up a great many. Hitherto I had stuck to my resolution of not eating animal food, and on this occasion consider’d, with my master Tryon, the taking every fish as a kind of unprovoked murder, since none of them had, or ever could do us any injury that might justify the slaughter. All this seemed very reasonable. But I had formerly been a great lover of fish, and, when this came hot out of the frying-pan, it smelt admirably well. I balanc’d some time between principle and inclination, till I recollected that, when the fish were opened, I saw smaller fish taken out of their stomachs; then thought I, “If you eat one another, I don’t see why we mayn’t eat you.” So I din’d upon cod very heartily, and continued to eat with other people, returning only now and then occasionally to a vegetable diet. So convenient a thing it is to be a reasonable creature, since it enables one to find or make a reason for everything one has a mind to do.

—Benjamin Franklin, Autobiography

A conclusion is the place where you got tired of thinking.

—Steven Wright, stand-up comedian

Nature knits up her kinds in a network, not
in a chain; but men can follow only by
chains because their language can’t handle
several things at once.

—Albrecht von Haller (tr. Howard Nemerov)
[Epigraph to Nemerov’s poem, “The Dependencies”]

. . . Argument has [n]ever been able to free the people from that enormous load of absurdity with which superstition has everywhere overwhelmed them.

—David Hume,  History of England

Doubt is not a pleasant condition, but certainty is an absurd one.

—Voltaire, Letter to Frederick William, Prince of Prussia (1770)

The greatest enemy of knowledge is not ignorance. It is the illusion of knowledge.

—Daniel J. Boorstin, The Discoverers (1983)

The great tragedy of Science — the slaying of a beautiful hypothesis by an ugly fact.

—Thomas Henry Huxley
Presidential Address at the British Association,
“Biogenesis and abiogenesis” (1870);
later published in Collected Essays, Vol. 8, p. 229.