The thinking man must oppose all cruelties no matter how deeply rooted in tradition or surrounded by a halo.

An idea is, in the end, always stronger than circumstances.

The great secret of success is to go through life as a person who never gets used up. That is possible for those who never argue and strive with people and facts, but in all experience retires upon themselves, and look for the ultimate cause of things in themselves.

We need a boundless ethic, one which will include the animals, too. Until we extend the circle of his compassions to all living things, we will not find peace.

We cannot abdicate our conscience to an organization, nor to a government.

No one may shut his eyes to think the pain, which is therefore not visible to him, is non-existent.

That's my private ant. You're liable to break its legs.