Darkness is absence of light. Shadow is diminution of light.

In whatever system where the weight attached to the wheel should be the cause of motion of the wheel, without any doubt the center of the gravity of the weight will stop beneath the center of its axle. No instrument devised by human ingenuity, which turns with its wheel, can remedy this effect. Oh, speculators about perpetual motion, how many vain chimeras have you created in the like quest. Go and take you place with the seekers after gold.

Painting is poetry that is seen rather than felt, and poetry is painting that is felt rather than seen.

The human being, creature of eyes, needs the image.

Strive to preserve your health; and in this you will better succeed in proportion as you keep clear of the physicians, for their drugs are a kind of alchemy concerning which there are no fewer books than there are medicines.

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.

Life well spent is long.