Nothing can be more destructive to ambition, and the passion for conquest, than the true system of astronomy. What a poor thing is even the whole globe in comparison of the infinite extent of nature!

It is the passions that do and undo everything.

I hate war, for it spoils conversation.

In vain we shall penetrate more and more deeply the secrets of the structure of the human body, we shall not dupe nature; we shall die as usual.

Nature intends that, at fixed periods, men should succeed each other by the instrumentality of death. We shall never outwit Nature; we shall die as usual.

A philospher sees the Earth as a large planet, travelling through the heavens, covered with fools

Hardly anyone knows how much is gained by ignoring the future.