ONE EVENING, a long time ago, in fact a very long time ago, specifically in the last year of the last century, that is, in 1599, “back when I still had my eyes!,” as the astronomer told Leibniz and the latter reported to the Philosophical Transactions, a new object appeared in the heavens over Bohemia. Never before had such a thing happened. It seemed to pop into existence from one moment to the next. “The existence of things until then had operated quite differently!” In a corner of the sky that had been ink-black since the time of the ancients there was now something irrefutably twinkling, a twinkling that stood in total contradiction to the doctrine of Aristotle positing the eternal perfection and perfect fixity of the celestial spheres. Yes, in the fifty-five spheres by which we were ostensibly bound nothing new was supposed to take place, nothing was ever to die, and nothing was to be born, either! That doctrine, as is well-known, the astronomer said, had long been preached by the Aristotelians of Prague on every street corner and in every lecture hall and even right into the Emperor’s ear. Now, perhaps you could claim that this twinkling had always been there and man had missed it, or that it bloomed into being only in the sublunary sphere, not so much higher really than the clouds, or even that it was a shared delusion, that it twinkled in reality on the surfaces of our retinas or on the insides of our heads, but you could not deny that something was twinkling. Something, in short, twinkled, the old astronomer told Leibniz, pausing briefly to peer into his telescope, pick up his quill, and write something down. Even in disputing what twinkled or where it twinkled you were admitting that it twinkled. That it twinkled was certain. “Simply put, it twinkled!” the astronomer cried. Not even the Aristotelians could deny that it twinkled, and the astronomer—though he had no formal training in mathematics or metaphysics, being the son of a sculptor who had whisked him into his workshop the moment he could speak and expected him from then on to hammer rather than ponder, to chisel rather than calculate, to sand and polish rather than observe and explain, who in general preached the virtues of the hand over those of the eye and mind and who even announced more than once that he could go on living if his eyes were plucked out but if his hands were cut off not—recalled dashing around Prague all night the night the new object appeared, forcing dogmatic Aristotelians of the prior generation to admit that something new was twinkling up there, and then tying those rigid old Aristotelians in philosophical knots. He would come upon an old Aristotelian and immediately tie him in knots. “No sooner had I happened upon another Aristotelian than I had tied him in some of the tightest possible philosophical knots, all on the basis of what he could see with his very own eyes,” Leibniz quoted the astronomer as saying. It wasn’t only he of course—all over Prague elderly Aristotelians were being set upon, made to look at the twinkling thing, and then tied in knots, simply scooped up out of their academic pens or snatched from their academic roosts and tied unceremoniously in knots—but he himself, even though probably not one person in Prague would so much as remember his name now (Kepler’s name they would remember, of course, but not his!), “tied at least ten or eleven Aristotelians in knots that night, tight knots, truly tight cosmological knots,” he said, “the kind of knots they would forever struggle to get out of, but would never be able to get out of as long as they lived because I’d actually used their own eyes to tie them. If you use your eyes, they’ll always squirm out of it, but if you use their eyes then they’re trapped, and in this case I used what their eyes had indubitably seen of that incontrovertibly twinkling object,” a heavenly object which, as Leibniz noted in a parenthetical addressed to the editor of the Philosophical Transactions, may correspond, if we permit for the possibility of the old man mixing up his years, to the supernova of 1604, what is now known, needless to say, he added, as Kepler’s Supernova. “The secret,” the astronomer told Leibniz, “is to tie a person up using his own retinal impressions, so the more he sees, the tighter he’s tied.”