1. “Art is never finished, only abandoned.”
2. "Every now and then go away, have a little relaxation, for when you come back to your work your judgment will be surer since to remain constantly at work will cause you to lose power of judgment. Go some distance away because then the work appears smaller, and more of it can be taken in at a glance, and a lack of harmony or portion is more readily seen."
3. “First study the science. Then practice the art which is born of that science.”
4. ”He who loves practice without theory is like the sailor who boards ship without a rudder and compass and never knows where he may cast.”
5. “Human subtlety will never devise an invention more beautiful, more simple or more direct than does nature because in her inventions nothing is lacking, and nothing is superfluous.”
6. ”Inequality is the cause of all local movements.”
7. “In rivers, the water that you touch is the last of what has passed and the first of that which comes; so with present time.”
8. “Iron rusts from disuse; stagnant water loses its purity and in cold weather becomes frozen; even so does inaction sap the vigor of the mind.”
9. "It is hard to have patience with people who say "There is no death" or "Death doesn't matter." There is death. And whatever is matters. And whatever happens has consequences, and it and they are irrevocable and irreversible. You might as well say that birth doesn't matter."
10. “Obstacles cannot crush me. Every obstacle yields to stern resolve. He who is fixed to a star does not change his mind.”
11. “Once you have flown, you will walk the earth with your eyes turned skyward; for there you have been, there you long to return.”
12. “Simplicity is the ultimate sophistication.”
13. "The faculty of imagination is both the rudder and the bridle of the senses."
14. "The method of awakening the Mind to a Variety of Inventions. ...a new kind of speculative invention, which though apparently trifling and almost laughable, is nevertheless of great utility in assisting the genius to find variety for composition. By looking attentively at old and smeared walls, or stones and veined marble of various colors, you may fancy that you see in them several compositions, landscapes, battles, figures in quick motion, strange countenances, and dresses, with an infinity of other objects. By these confused lines the inventive genius is excited to new exertions."
15. “The noblest pleasure is the joy of understanding.”
16. “The painter who draws by practice and judgment of the eye without the use of reason is like the mirror which reproduces within itself all the objects which are set opposite to it without knowledge of the same.”
17. “Why does the eye see a thing more clearly in dreams than the imagination when awake?”
18. “You do ill if you praise, but worse if you censure, what you do not understand.”
