A man's interest in the world is only the overflow from his interest in himself. When you are a child your vessel is not yet full;so you care for nothing but your own affairs. When you grow up, your vessel overflows; and you are a politician, a philosopher, or an explorer and adventurer. In old age the vessel dries up: there is no overflow: you are a child again.

Stop being Jews and start being human beings.

If you cannot attain knowledge without torturing a dog, you must do without knowledge.

Use your health, even to the point of wearing it out. That is what it is for. Spend all you have before you die; do not outlive yourself.

I can't turn your soul on. Leave me those feelings; and you can take away the voice and the face. They are not you.

We must not stay as we are, doing always what was done last time, or we shall stick in the mud. Yet neither must we undertake a new world as catastrophic Utopians, and wreck our civilization in our hurry to mend it.

When you want to put something into your part that is not in the play, you must ask the author-or some other author-to lead up to the interpolation for you. Never forget that the effect of a line may depend not on its delivery, but on something said earlier in the play, either by somebody else or by yourself, and that if you change it, it may be necessary to change the whole first act as well.