I have lived one hundred years; and I die with the consolation of never having thrown the slightest ridicule upon the smallest virtue.

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!

The Art of Flying is but newly invented, twill improve by degrees, and in time grow perfect; then we may fly as far as the Moon.

People almost always do great things without knowing how to do them, and are quite surprised to have done them.

To despise theory is to have the excessively vain pretension to do without knowing what one does, and to speak without knowing what one says.

Leibniz never married; he had considered it at the age of fifty; but the person he had in mind asked for time to reflect. This gave Leibniz time to reflect, too, and so he never married.

It is the passions that do and undo everything.