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.

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.

To be happy, one must have a good stomach and a bad heart.

I hate war, for it spoils conversation.

It takes time to ruin a world, but time is all it takes.

If I had my hand full of truth, I would take good care how I opened it.

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.