The gem cannot be polished without friction nor man without trials.

To know and not do, is to not yet know.

If what one has to say is not better than silence, then one should keep silent.

Earnest in practicing the ordinary virtues, and careful in speaking about them, if, in his practice, he has anything defective, the superior man dares not but exert himself; and if, in his words, he has any excess, he dares not allow himself such license.

The one who was born a genius can't win against the one who tries, and the one who tries can't win against the one who enjoys.

If doing what ought to be done be made the first business and success a secondary consideration--is not this the way to exalt virtue?

Settle one difficulty, and you keep a hundred away.