Ask advice of him who governs himself well.

The Bactrian have two humps; the Arabian one only. They are swift in battle and most useful to carry burdens. This animal is extremely observant of rule and measure, for it will not move if it has a greater weight than it is used to, and if it is taken too far it does the same, and suddenly stops and so the merchants are obliged to lodge there.

Truly man is the king of beasts, for his brutality exceeds them. We live by the death of others. We are burial places.

He who possesses most must be most afraid of loss.

Tears come from the heart and not from the brain

Having wandered some distance among gloomy rocks, I came to the entrance of a great cavern ... Two contrary emotions arose in me: fear and desire--fear of the threatening dark cavern, desire to see whether there were any marvelous things in it.

Perspective is a most subtle discovery in mathematical studies, for by means of lines it causes to appear distant that which is near, and large that which is small.