I am delighted to know that Principia Mathematica can now be done by machinery. . . I am quite willing to believe that anything in deductive logic can be done by machinery.

When a man tells you that he knows the exact truth about anything you are safe in inferring that he is an inexact man.

To avoid the various foolish opinions to which mankind are prone, no superhuman genius is required. A few simple rules will keep you, not from all error, but from silly error.

It is a curious and painful fact that almost all the completely futile treatments that have been believed in during the long history of medical folly have been such as caused acute suffering to the patient. When anesthetics were discovered, pious people considered them an attempt to evade the will of God. It was pointed out, however, that when God extracted Adam's rib He put him into a deep sleep. This proved that anesthetics are all right for men; women, however, ought to suffer, because of the curse of Eve.

Very many people spend money in ways quite different from those that their natural tastes would enjoin, merely because the respect of their neighbors depends upon their possession of a good car and their ability to give good dinners. As a matter of fact, any man who can obviously afford a car but genuinely prefers travels or a good library will in the end be much more respected than if he behaved exactly like everyone else.

Religion may in most of its forms be defined as the belief that the gods are on the side of the government.

A man without a bias cannot write interesting history - if indeed such a man exists.