There is nothing that has caused me to meditate more on Plato's secrecy and sphinx-like nature, than the happily preserved petit fait that under the pillow of his death-bed there was found no 'Bible,' nor anything Egyptian, Pythagorean, or Platonic - but a book of Aristophanes. How could even Plato have endured life - a Greek life which he repudiated - without an Aristophanes!

I devote myself to what I love the most, and for this very reason I hesitate to designate it with lofty words: I do not want to risk believing that it is a sublime compulsion, a law, which I obey: I love what I love the most too much to wish to appear to it as one compelled.

Thinking has to be learned in the way dancing has to be learned.

We no longer love our knowledge enough once we have passed it on.

Mathematics is merely the means to a general and ultimate knowledge of man.

Never to read another book that was born and baptized (with ink) at the same time.

In a friend one should have ones best enemy. You should be closest to him with your heart when you resist him.