Physics is unable to stand on its own feet, but needs a metaphysics on which to support itself, whatever fine airs it may assume towards the latter.

There is only one inborn error. and that is the notion that we exist in order to be happy.

Genius is an intellect that has become unfaithful to its destiny.

To call the world God is not to explain it; it is only to enrich our language with a superfluous synonym.

I observed once to Goethe that when a friend is with us we do not think the same of him as when he is away. He replied, "Yes! because the absent friend is yourself, and he exists only in your head; whereas the friend who is present has an individuality of his own, and moves according to laws of his own, which cannot always be in accordance with those which you form for yourself.

Poetry is related to philosophy as experience is related to empirical science. Experience makes us acquainted with the phenomenon in the particular and by means of examples, science embraces the whole of phenomena by means of general conceptions. So poetry seeks to make us acquainted with the Platonic Ideas through the particular and by means of examples. Philosophy aims at teaching, as a whole and in general, the inner nature of things which expresses itself in these. One sees even here that poetry bears more the character of youth, philosophy that of old age.

As the strata of the earth preserve in succession the living creatures of past epochs, so the shelves of libraries preserve in succession the errors of the past and their expositions, which like the former were very lively and made a great commotion in their own age but now stand petrified and stiff in a place where only the literary palaeontologist regards them.