Mathematicians are like lovers. Grant a mathematician the least principle, and he will draw from it a consequence which you must also grant him, and from this consequence another.

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.

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!

An educated mind is, as it were, composed of all the minds of preceding ages.

There is nothing one sees oftener than the ridiculous and magnificent, such close neighbors that they touch.

A true philosopher is like an elephant; he never puts the second foot down until the first one is solidly in place.

It is the passions that do and undo everything.