A writer who wishes to be read by posterity must not be averse to putting hints which might give rise to whole books, or ideas for learned discussions, in some corner of a chapter so that one should think he can afford to throw them away by the thousand.

There were honest people long before there were Christians and there are, God be praised, still honest people where there are no Christians. It could therefore easily be possible that people are Christians because true Christianity corresponds to what they would have been even if Christianity did not exist.

If you are going to build something in the air it is always better to build castles than houses of cards.

So-called professional mathematicians have, in their reliance on the relative incapacity of the rest of mankind, acquired for themselves a reputation for profundity very similar to the reputation for sanctity possessed by theologians.

They do not think, therefore they are not.

Ambition and suspicion always go together.

Prejudices are so to speak the mechanical instincts of men: through their prejudices they do without any effort many things they would find too difficult to think through to the point of resolving to do them.