Thought is subversive and revolutionary, destructive and terrible, Thought is merciless to privilege, established institutions, and comfortable habit. Thought is great and swift and free.

What is wanted is not the will to believe, but the will to find out, which is the exact opposite.

Love is wise; hatred is foolish. In this world, which is getting more and more closely interconnected, we have to learn to tolerate each other, we have to learn to put up with the fact that some people say things that we don't like. We can only live together in that way. But if we are to live together, and not die together, we must learn a kind of charity and a kind of tolerance, which is absolutely vital to the continuation of human life on this planet.

While the dogmatist is harmful, the sceptic is useless ...; one is certain of knowing, the other of not knowing. What philosophy should dissipate is certainty, whether of knowledge or of ignorance. Knowledge is not so precise a concept as is commonly thought. Instead of saying 'I know this', we ought to say 'I more or less know something more or less like this'. ... Knowledge in practical affairs has not the certainty or the precision of arithmetic.

The more intense has been the religion of any period and the more profound has been the dogmatic belief, the greater has been the cruelty and the worse has been the state of affairs.

The universe may have a purpose, but nothing we know suggests that, if so, this purpose has any similarity to ours.

I don't like the spirit of socialism - I think freedom is the basis of everything.