What you do not want done to yourself, do not do to others.

Everyone calls his son his son, whether he has talents or has not talents.

Sincerity is that whereby self-completion is effected, and its way is that by which man must direct himself.

The gentleman has nine cares. In seeing he is careful to see clearly; in hearing he is careful to hear distinctly; in his looks he is careful to be kind, in his manner to be respectful, in his words to be sincere, in his work to be diligent. When in doubt he is careful to ask for information; when angry he has a care for the consequences; and when he sees a chance for gain, he thinks carefully whether the pursuits of it would be right.

He who cannot describe the problem will never find the solution to that problem.

Knowing what's correct and not doing it, it's the worst cowardice.

If I give a student one-fourth of what he should know, I expect him to get the other three-fourths himself, otherwise I do not want him as a student.