The eye transmits its own image through the air to all the objects which face it, and also receives them on its own surface, whence the "sensus communis" takes them and considers them.

Music... is the shaping of the invisible.

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.

Being engulfed in practice without delicate knowledge related to it, is in many ways like entering a ship without knowing where it is headed.

There is no object so large but that at a great distance from the eye it does not appear smaller than a smaller object near.

I have solved what color is, however ; I still have no idea about what line is.

Nature never breaks her own laws.