If an opinion contrary to your own makes you angry, that is a sign that you are subsciously aware of having no good reason for thinking as you do. [...] 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. So whenever you find yourself getting angry about a difference of opinion, be on your guard; you will probably find, on examination, that your belief is going beyond what the evidence warrants.

The most valuable things in life are not measured in monetary terms. The really important things are not houses and lands, stocks and bonds, automobiles and real state, but friendships, trust, confidence, empathy, mercy, love and faith.

If throughout your life you abstain from murder, theft, fornication, perjury, blasphemy, and disrespect toward your parents, church, and your king, you are conventionally held to deserve moral admiration even if you have never done a single kind, generous or useful action. This very inadequate notion of virtue is an outcome of taboo morality, and has done untold harm.

The observer, when he seems to himself to be observing a stone, is really, if physics is to be believed, observing the effects of the stone upon himself.

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.

(on A History of Western Philosophy) I was sometimes accused by reviewers of writing not a true history but a biased account of the events that I arbitrarily chose to write of. But to my mind, a man without a bias cannot write interesting history - if, indeed, such man exists.

The best practical advice I can give to the present generation is to practice the virtue which the Christians call love.