As regards this vice, we read that the peacock is more guilty of it than any other animal. For it is always contemplating the beauty of its tail, which it spreads in the form of a wheel, and by its cries attracts to itself the gaze of the creatures that surround it. And this is the last vice to be conquered.

O time! swift devourer of all created things!

It is no small benefit on finding oneself in bed in the dark to go over again in the imagination the main lines of the forms previously studied, or other noteworthy things conceived by ingenious speculation.

Any color is more distinctly seen when opposed to its contrary: thus, black on white, blear near yellow, green near red, and so on.

Fire destroys falsehood, that is sophistry, and restores truth, driving out darkness.

There are three classes of people: those who see, those who see when they are shown, those who do not see.

The lover is moved by the beloved object as the senses are by sensual objects; and they unite and become one and the same thing. The work is the first thing born of this union; if the thing loved is base the lover becomes base.