In short, the Chamberlain explained, a battle over the state of Heinrich’s mind, or soul, was a battle on favorable terrain. “As soon as Archduke Matthias uttered the words ‘Heinrich’s mind’ or ‘Heinrich’s soul’ or ‘Heinrich’s madness,’ or ‘Heinrich’s hereditary madness,’ the battle was won.”

He added: “And Matthias must have known that, for he never once uttered those words.”

Rather than planting his flag inside Heinrich’s head, Matthias has planted it outside it, on the grounds of Heinrich’s behavior on the night of November fourteenth, his observed and mutually agreed upon behavior, his indubitable and incontrovertible behavior, his well-witnessed crime, the magnitude, iniquity, and oddity of which, regardless of what was going through his mind as he perpetrated it, ought to disqualify him, so argued the Archduke, from the office of Holy Roman Emperor. That was the extent of the Archduke’s argument, and despite its apparent simplicity, in seeming to reason simply that a prince who has dismembered and defenestrated the daughter of a tradesman ought not ascend to the throne, it was in fact terrifically subtle. “An emperor cannot behave this way: That’s been Matthias’s constant refrain in Frankfurt,” said the Court Chamberlain, and, leaning toward the astronomer, he whispered: “I doubt whether His Majesty appreciates his brother’s cunning in selecting that verb. Like all world-class politicians, the Archduke is, above all, a world-class wordsmith. An emperor,” he repeated, enunciating each word, eyes alight at the Archduke’s artfulness, “cannot behave this way.

“And so,” the Chamberlain continued, “our strategy has changed accordingly.”

The astronomer put an eye socket to his telescope, picked up his quill, and wrote down a string of numbers. There was, he declared, pulling his pocket watch from his rags, little more than an hour now till the solar eclipse.

Leibniz asked him: What exactly did the Prince do to the barber-surgeon’s daughter? And why?

“Those were my questions, also!” cried the astronomer. “Yes, what did he do, and why did he do it? Was there, in other words, a reason? What of the jealous rage Margaretha had mentioned? My questions also. But I suspected I would not get the truth from these two.”

“Yes,” the Chamberlain had said, the astronomer continued, “our strategy has changed accordingly—and here is where you come in. Since Matthias has brought the battle to the shores of Heinrich’s behavior, we must engage him there. We must prove what we know to be true, that the night of November fourteenth was a bizarre aberration, that Heinrich’s behavior now is behavior befitting a Holy Roman Emperor. We must prove by his behavior that he is sane.”

The astronomer: “I suddenly wondered what kind of minuets Gottfried had been instructed to teach Margaretha … In retrospect, the way he was teaching her to eat seemed completely insane. I remembered what he’d said about soup, about serving tongs, about stone fruit. Gottfried was intentionally inculcating in her the manners of a madwoman, I realized. He was not there to help her wed…”