The contrast between Leonardo and Michelangelo is an allegory of the arts of modern times. Leonardo left copious notes of his observations on nature and the world around him, but little about his feelings or his inner life. Michelangelo, in his letters, his poetry, in biographies by his friends and students Vasari and Condivi, in conversations with Francisco de Hollanda and others, left us vivid revelations and eloquent chronicles of himself. Leonardo, the self-styled "disciple of experience," was a hero of the effort to re-create the world from the shapes and forms and sensations out there. But Michelangelo, prophet of the sovereign self, found mysterious resources within. These two greatest figures of Italian Renaissance art dramatized a modern movement from craftsman to artist. If Leonardo could be called the Aristotle—practical-minded organizer and surveyor of experience—Michelangelo would be the Plato, seeker after the perfect idea.