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.

Be isolated, be ignored, be attacked, be in doubt, be frightened, but do not be silenced.

In a Balkan country, not so many years ago, a party which had been beaten by a narrow margin in a general election retrieved its fortunes by shooting a sufficient number of the representatives of the other side to give it a majority. . . . Cromwell and Robespierre . . . acted likewise.

More cranks take up unfashionable errors than unfashionable truths.

Perhaps the nuclear physicists have come so near to the ultimate secrets that He thinks it time to bring their activities to a stop. And what simpler method could He devise than to let them carry their ingenuity to the point where they exterminate the human race?

Frege has the merit of ... finding a third assertion by recognising the world of logic which is neither mental nor physical.

The man who suffers from a sense of sin is suffering from a particular kind of self-love. In all this vast universe the thing that appears to him of most importance is that he himself should be virtuous. It is a grave defect in certain forms of traditional religion that they have encouraged this particular kind of self-absorption.