Truth was always but the daughter of time.

When counting, try not to mix chickens with blessings.

Now do you not see that the eye embraces the beauty of the whole world? It counsels and corrects all the arts of mankind... it is the prince of mathematics, and the sciences founded on it are absolutely certain. It has measured the distances and sizes of the stars it has discovered the elements and their location... it has given birth to architecture and to perspective and to the divine art of painting.

I am not to blame for putting forward, in the course of my work on science, any general rule derived from a previous conclusion.

Men born in hot countries love the night because it refreshes them and have a horror of light because it burns them.

Obstacles cannot crush me. Every obstacle yields to stern resolve. He who is fixed to a star does not change his mind.

He who cannot establish dominion over himself will have no dominion over others.