While I thought that I was learning how to live, I have been learning how to die.

All objects transmit their image to the eye in pyramids and the nearer to the eye these pyramids are intersected the smaller will the image appear of the objects which cause them.

Thirst will parch your tongue and your body will waste through lack of sleep ere you can describe in words that which painting instantly sets before the eye.

Thou, O God, dost sell us all good things at the price of labor.

There is no higher or lower knowledge, but one only, flowing out of experimentation.

Depth and strength of a human character are defined by its moral reserves.

It vexes me greatly that having to earn my living has forced me to interrupt the work and to attend to small matters.