Make yourself a master of perspective, then acquire perfect knowledge of the proportions of men and other animals.

It is an acknowledged fact that we perceive errors in the work of others more readily than in our own.

Affective gestures pointing to things near either in time or space should be made with the hand not very far from the body of the person pointing; and if these things are distant, the hand of the painter should be more extended and the face turned toward the person to whom he is addressing the demonstration.

Experience does not err. Only your judgments err by expecting from her what is not in her power.

Details make perfection, and perfection is not a detail.

... we might say that the earth has a spirit of growth; that its flesh is the soil, its bones the arrangement and connection of the rocks of which the mountains are composed, its cartilage the tufa, and its blood the springs of water.

Therefore, O students, study mathematics and do not build without foundations.