Reprove your friend in secret and praise him openly.

Fear arises sooner than anything else.

Intellectual passion dries out sensuality.

The mind that engages in subjects of too great variety becomes confused and weakened.

Love shows itself more in adversity than in prosperity; as light does, which shines most where the place is darkest.

Those who are enamoured of practice without science are like a pilot who goes into a ship without rudder or compass and never has any certainty of where he is going. Practice should always be based upon a sound knowledge of theory.

It vexes me greatly that having to earn my living has forced me to interrupt the work and to attend to small matters.