No idea is isolated, but is only what it is among all ideas.

There are three kinds of explanation in science: explanations which throw a light upon, or give a hint at a matter; explanations which do not explain anything; and explanations which obscure everything.

Religion is usually nothing but a supplement to or even a substitute for education, and nothing is religious in the strict sense which is not a product of freedom. Thus one can say: The freer, the more religious; and the more education, the less religion.

There is so much poetry, and yet nothing is more rare than a poetic work. This is what the masses make out of poetical sketches, studies, aphorisms, trends, ruins, and raw material.

How many authors are there among writers? Author means originator.

He who does not become familiar with nature through love will never know her.

A classical work doesn't ever have to be understood entirely. But those who are educated and who are still educating themselves must desire to learn more and more from it.