Perspective is to painting what the bridle is to the horse, the rudder to a ship.

The mind of the painter must resemble a mirror, which always takes the colour of the object it reflects and is completely occupied by the images of as many objects as are in front of it.

Surely when a man is painting a picture he ought not refuse to hear any man's opinion... Since men are able to form a true judgement as to the works of nature, how much more does it behoove us to admit that they are able to judge our faults.

He only moves toward the perfection of his art whose criticism surpasses his achievement.

Thus it is with a deaf and dumb person who, when he sees two men in conversation - although he is deprived of hearing - can nevertheless understand, from the attitudes and gestures of the speakers, the nature of their discussion.

A painter should begin every canvas with a wash of black, because all things in nature are dark except where exposed by the light.