On the morning of 3 January Nietzsche had just left his lodgings when he saw a cab-driver beating his horse in the Piazza Carlo Alberto. Tearfully, the philosopher flung his arms around the animal's neck, and then collapsed. The small crowd that gathered around him attracted Davide Fino, who had his lodger carried back to his room. After lying unconscious or at least motionless for a while on a sofa, Nietzsche became boisterous, singing, shouting, thumping at the piano. He probably thought he was clowning deliberately.… But the 'inspired clowning' which had already been hard to control by the end of November was now in unchallengeable possession of his mind. He wrote notes to the King of Italy ('My beloved Umberto'), the royal house of Baden ('My children'), and the Vatican Secretary of State. He would go to Rome on Tuesday, he said, to meet the pope and the...