Daily life is more instructive than the most effective book.

Every decided colour does a certain violence to the eye, and forces the organ to opposition.

Go to the place where the thing you wish to know is native; your best teacher is there. Where the thing you wish to know is so dominant that you must breathe its very atmosphere, there teaching is moat thorough, and learning is most easy. You acquire a language most readily in the country where it is spoken; you study mineralogy boat among miners; and so with everything else.

Die Mathematiker sind eine Art Franzosen. Spricht man zu ihnen, so übersetzen sie alles in ihre eigene Sprache, und so wird es alsobald etwas ganz anderes. Mathematicians are a kind of Frenchmen. Whenever you say anything or talk to them, they translate it into their own language, and right away it is something completely different.

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

To the man of thought almost nothing is really ridiculous.

Life belongs to the living, and he who lives must be prepared for changes.