This work should commence with the conception of man, and should describe the nature of the womb, and how the child inhabits it, and in what stage it dwells there, and the manner of its quickening and feeding, and its growth, and what interval there is between one stage of growth and another, and what thing drives it forth from the body of the mother, and for what reason it sometimes emerges from the belly of its mother before the due time.

Having wandered some distance among gloomy rocks, I came to the entrance of a great cavern ... Two contrary emotions arose in me: fear and desire--fear of the threatening dark cavern, desire to see whether there were any marvelous things in it.

Not to appreciate life, all of life, is not to deserve it.

Of the four elements water is the second in weight and the second in respect of mobility. It is never at rest until it unites with the sea.

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

Some promises and time disappoint us

Painting is concerned with the ten things you can see: these are darkness and brightness, substance and color, form and place, remoteness and nearness, movement and rest.