We must learn to love, learn to be kind, and this from the earliest youth; if education or chance give us no opportunity to practice these feelings, our soul becomes dry and unsuited even to understanding the tender inventions of loving people.

It is perhaps just dawning on five or six minds that physics, too, is only an interpretation and exegesis of the world (to suit us, if I may say so!) and not a world-explanation.

I love him who laboureth and inventeth, that he may build the house for the Superman, and prepare for him earth, animal, and plant: for thus seeketh he his own down-going.

If you are considering marriage, ask yourself one question: Will I still enjoy talking with her when I'm old?

The love of power is the demon of mankind.

Perhaps no one as yet has been truthful enough about what "truthfulness" is.

Laughter means: taking a mischievous delight in someone else's uneasiness, but with a good conscience.