Wicked thoughts and worthless efforts gradually set their mark on the face, especially the eyes.

Empirical sciences prosecuted purely for their own sake, and without philosophic tendency are like a face without eyes.

It is difficult, if not impossible, to define the limit of our reasonable desires in respect of possessions.

There is a wide difference between the original thinker and the merely learned man.

To be alone is the fate of all great minds—a fate deplored at times, but still always chosen as the less grievous of two evils.

There is not a grain of dust, not an atom that can become nothing, yet man believes that death is the annhilation of his being.

A happy life is impos­si­ble; the best that a man can attain is a heroic life.