More and more people are becoming unable to accept traditional [religious] beliefs. If they think that, apart from these beliefs, there is no reason for kindly behaviour, the results may be needlessly unfortunate. That is why it is important to show that no supernatural reasons are needed to make [people] kind and to prove that only through kindness can the human race achieve happiness.

Prophets, mystics, poets, scientific discoverers are men whose lives are dominated by a vision; they are essentially solitary men . . . whose thoughts and emotions are not subject to the dominion of the herd.

Morally, a philosopher who uses his professional competence for anything except a disinterested search for truth is guilty of a kind of treachery.

[Industrialism's soon diminishing] capacity to supply human needs could be prevented if men exercised any restraint or foresight in their present frenzied exploitation.

The desire to understand the world and the desire to reform it are the two great engines of progress, without which human society would stand still or retrogress.

I believe four ingredients are necessary for happiness: health, warm personal relations, sufficient means to keep you from want, and successful work.

If an opinion contrary to your own makes you angry, that is a sign that you are subconsciously aware of having no good reason for thinking as you do.