One can have no smaller or greater mastery than mastery of oneself. How to do it?
— Leonardo da Vinci

There is a connection, hard to explain logically but easy to feel, between achievement in public life and progress in the arts. The age of Pericles was also the age of Phidias. The age of Lorenzo de Medici was also the age of leonardo da Vinci. The age of Elizabeth was also the age of Shakespeare. And the New Frontier for which I campaign in public life, can also be a New Frontier for American art.
— John F. Kennedy

He bores me. He ought to have stuck to his flying machine. On Leonardo Da Vinci
— Pierre Auguste Renoir

Don't say you don't have enough time. You have exactly the same number of hours per day that were given to Helen Keller, Pasteur, Michaelangelo, Mother Teresa, Leonardo da Vinci, Thomas Jefferson, and Albert Einstein.
— H. Jackson Brown, Jr.

In Italy for thirty years under the Borgias they had warfare, terror, murder and bloodshed but they produced Michelangelo, Leonardo da Vinci and the Renaissance. In Switzerland, they had brotherly love; they had five hundred years of democracy and peace and what did that produce? The cuckoo clock.
— Orson Welles