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

Where there is shouting, there is no true knowledge.

O speculators about perpetual motion, how many vain chimeras have you created in the like quest? Go and take your place with the seekers after gold.

Feathers shall raise men even as they do birds towards heaven :- That is by letters written with their quills.

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.

Truth was the only daughter of Time.

All thoughts start from emotions.