Sculptured figures which appear in motion, will, in their standing position, actually look as if they were falling forward.

A deaf and dumb person who sees two men in conversation - may nevertheless understand from the attitudes and gestures of the speakers, how well their discussion is getting along.

The senses are of the earth, the reason stands apart from them in contemplation.

Learning acquired in youth arrests the evil of old age; and if you understand that old age has wisdom for its food, you will so conduct yourself in youth that your old age will not lack for nourishment.

The good painter must paint two things: a person and the essence of his soul.

Medicine is the restoration of discordant elements; sickness is the discord of the elements infused into the living body.

If you find from your own experience that something is a fact and it contradicts what some authority has written down, then you must abandon the authority and base your reasoning on your own findings.