Beware of dissipating your powers; strive constantly to concentrate them.

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.

Those only obtain love, for the most part, who seek it not.

Beauty vanishes; virtue is lasting.

God could cause us considerable embarrassment by revealing all the secrets of nature to us: we should not know what to do for sheer apathy and boredom.

Nothing is so atrocious as fancy without taste.

Moral epochs have their course as well as the seasons. We can no more hold them fast than we can hold sun, moon, and stars. Our faults perpetually return upon us; and herein lies the subtlest difficulty of self-knowledge.