Religion is something left over from the infancy of our intelligence, it will fade away as we adopt reason and science as our guidelines.

There is much pleasure to be gained from useless knowledge.

Science can teach us, and I think our hearts can teach us, no longer to look around for imaginary supporters, no longer to invent allies in the sky, but rather to look to our own efforts here below to make the world a fit place to live.

From India to Spain, the brilliant civilization of Islam flourished. What was lost to christendom at this time was not lost to civilization, but quite the contrary.

Throughout the long period of religious doubt, I had been rendered very unhappy by the gradual loss of belief, but when the process was completed, I found to my surprise that I was quite glad to be done with the whole subject.

The more things a man is interested in, the more opportunities of happiness he has and the less he is at the mercy of fate, since if he loses one thing he can fall back upon another.

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.