The philosopher ought never to try to avoid the duty of making up his mind.

The materialist assumption that spiritual substances do not exist is as much an act of faith as the religious belief in the reality of angels.

The truly great books are the few books that are over everybody's head all of the time.

Ask others about themselves, at the same time, be on guard not to talk too much about yourself.

To agree without understanding is inane. To disagree without understanding is impudent.

A lecture has been well described as the process whereby the notes of the teacher become the notes of the student without passing through the mind of either.

Erotic or sexual love can truly be love if it is not selfishly sexual or lustful.