In praise there is more obtrusiveness than in blame.

It is possible that the production of genius is reserved to a limited period of mankind's history.

Faith, indeed, has up to the present not been able to move real mountains, although I do not know who assumed that it could. But it can put mountains where there are none.

Without meaning, without substance, without aim: a mere 'public opinion'.

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.

Shared joys make a friend, not shared sufferings.

Whoever reaches his ideal transcends it eo ipso.