Anything you're good at contributes to happiness.

You may reasonably expect a man to walk a tightrope safely for ten minutes; it would be unreasonable to do so without accident for two hundred years.

It is only theory that makes men completely incautious.

If you had the power to destroy the world, would you do so?

To be without some of the things you want is an indispensable part of happiness.

To save the world requires faith and courage: faith in reason, and courage to proclaim what reason shows to be true.

The use of force stands in need of control by a public neutral authority, in the interests of liberty no less than of justice. Within a nation, this public authority will naturally be the state; in relations between nations, if the present anarchy is to cease, it will have to be some international parliament.