Nature is never so admired as when she is understood.

Behold a universe so immense that I am lost in it. I no longer know where I am. I am just nothing at all. Our world is terrifying in its insignificance.

If I held all the thoughts of the world in my hand, I would be careful not to open it.

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.

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.

There are three things I have loved but never understood. Art, music and women.