“I never considered a difference of opinion in politics, in religion, in philosophy, as cause for withdrawing from a friend.”

“In our country religion is not different from philosophy and religion & philosophy don’t differ from science.”

“The modern habit of saying "This is my opinion, but I may be wrong" is entirely irrational. If I say that it may be wrong, I say that is not my opinion. The modern habit of saying "Every man has a different philosophy; this is my philosophy and it suits me" – the habit of saying this is mere weak-mindedness. A cosmic philosophy is not constructed to fit a man; a cosmic philosophy is constructed to fit a cosmos. A man can no more possess a private religion than he can possess a private sun and moon.”

“The peculiarity of the evidence of mathematical truths is, that all the argument is on one side. There are no objections, and no answers to objections. But on every subject on which difference of opinion is possible, the truth depends on a balance to be struck between two sets of confliting reasons. Even in natural philosophy, there is always some other explanation possible of the same facts; some geocentric theory instead of heliocentric, some phlogiston instead of oxygen; and it has to be shown why that other theory cannot be the true on: and until this is shown, and until we know how it is shown, we do not understand the grounds of our opinion. But when we turn to subjects infinitely more complicated, to morals, religion, politics, social relations, and the business of life, three-fourths of the arguments for every disputed opinion consist in dispelling the appearances which favour some opinion different from it.”

“I know it is the itch between the legs which causes everything-Wars, Religions, Marriages, Elections, Families, Globalization, Trade, Literature, Science, and for me Philosophy.”

“In philosophy, or religion, or ethics, or politics, two and two might make five, but when one was designing a gun or an aeroplane they had to make four.”