Man can only endure a certain degree of unhappiness; what is beyond that either annihilates him or passes by him and leaves him apathetic

Life is not anything, but an opportunity for something.

Who can think wise or stupid things at all that were not thought already in the past.

Most man only care for science so far as they get a living by it, and that they worship even error when it affords them a subsistence.

Without my attempts in natural science, I should never have learned to know mankind such as it is. In nothing else can we so closely approach pure contemplation and thought, so closely observe the errors of the senses and of the understanding, the weak and strong points of character.

The force of a language does not consist of rejecting what is foreign but of swallowing it.

An actor should take lessons from a painter and a sculptor.