The mark of highest originality lies in the ability to develop a familiar idea so fruitfully that it would seem no one else would ever have discovered so much to be hidden in it.

You acquire a language most readily in the country where it is spoken; you study mineralogy best among miners; and so with everything else.

No one knows what he is doing so long as he is acting rightly; but of what is wrong one is always conscious.

If I work incessantly to the last, nature owes me another form of existence when the present one collapses.

Energy is the basis of everything. Every Jew, no matter how insignificant, is engaged in some decisive and immediate pursuit of a goal... It is the most perpetual people of the earth.

He is a man whom it is impossible to please, because he is never pleased with himself.

A vain man can never be altogether rude. Desirous as he is of pleasing, he fashions his manners after those of others.