Never underestimate the power of human stupidity.

If it can't be expressed in figures, it is not science; it is opinion. It has long been known that one horse can run faster than another - but which one? Differences are crucial.

To stay young requires unceasing cultivation of the ability to unlearn old falsehoods.

Secrecy is the beginning of tyranny

An armed man need not fight.

The most important lesson in the writing trade is that any manuscript is improved if you cut away the fat.

On two subjects the overwhelming majority of people regarded their own opinions as Absolute Truth, and sincerely believed that anyone who disagreed with them was immoral, outrageous, sinful, sacrilegious, offensive, intolerable, stupid, illogical, treasonable, actionable, against the public interest, ridiculous, and obscene. The two subjects were (of course) sex and religion.