It is not to everyone's taste that truth should be pronounced pleasant. But at least let no one believe that error becomes truth when it is pronounced unpleasant.

Phlegmatic natures can be inspired to enthusiasm only by being made into fanatics.

Mathematics would certainly have not come into existence if one had known from the beginning that there was in nature no exactly straight line, no actual circle, no absolute magnitude.

We ought to face our destiny with courage.

Nothing has been purchased more dearly than the little bit of reason and sense of freedom which now constitutes our pride.

Even the most beautiful scenery is no longer assured of our love after we have lived in it for three months, and some distant coast attracts our avarice: possessions are generally diminished by possession.

To become the founder of a new religion one must be psychologically infallible in one's knowledge of a certain average type of souls who have not yet recognized that they belong together.