Those who are enamoured of practice without science are like a pilot who goes into a ship without rudder or compass and never has any certainty of where he is going. Practice should always be based upon a sound knowledge of theory.

Instrumental or mechanical science is the noblest and above all others, the most useful.

Who sows virtue reaps honor.

Poor is the man who desires a lot

Nothing is more apt to deceive us than our own judgment of our work. We derive more benefit from having our faults pointed out by our enemies than from hearing the opinions of friends.

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.

I'm not contented to capture the world. I want to change it.