The young man should first learn perspective, then the proportions of objects. Next, copy work after the hand of a good master, to gain the habit of drawing parts of the body well; and then to work from nature, to confirm the lessons learned.

Though I may not . . . be able to quote other authors, I shall rely on that which is much greater and more worthy - on experience.

Art lives from constraints and dies from freedom.

The motive power is the cause of all life.

Whoever despises the high wisdom of mathematics nourishes himself on delusion and will never still the sophistic sciences whose only product is an eternal uproar.

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

Those who are in love with practice without knowledge are like the sailor who gets into a ship without rudder or compass and who never can be certain whether he is going. Practice must always be founded on sound theory, and to this Perspective is the guide and the gateway; and without this nothing can be done well in the matter of drawing.