I wish to work miracles.

Inequality is the cause of all local movements.

The first object of the painter is to make a flat plane appear as a body in relief and projecting from that plane

After painting comes Sculpture, a very noble art, but one that does not in the execution require the same supreme ingenuity as the art of painting, since in two most important and difficult particulars, in foreshortening and in light and shade, for which the painter has to invent a process, sculpture is helped by nature. Moreover, Sculpture does not imitate color which the painter takes pains to attune so that the shadows accompany the lights.

But to me all sciences seem vain and full of error that are not born of experience, mother of all certainty, and do not terminate in an actual experience.

Every now and then go away, have a little relaxation, for when you come back to your work your judgment will be surer. Go some distance away because then the work appears smaller and more of it can be taken in at a glance and a lack of harmony and proportion is more readily seen.

Test knowledge through experience, be prepared to make mistakes, and be persistent about it.