In 1481, Pope Sixtus IV summoned Botticelli and other prominent Florentine and Umbrian artists to fresco the walls of the Sistine Chapel. The iconological program was the supremacy of the Papacy. Sandro's contribution included the Temptations of Christ, the Punishment of the Rebels and Trial of Moses. He returned to Florence, and "being of a sophistical turn of mind, he there wrote a commentary on a portion of Dante and illustrated the Inferno which he printed, spending much time over it, and this abstention from work led to serious disorders in his living." Thus Vasari characterized the...