¹ The central idea of this paper was inspired by Alessandro Barchiesi, and encouraged by Nicholas Purcell, and I am grateful to both of them; Gregory Hutchinson was kind enough to point out that an attractive thesis did not in itself make a convincing argument, and Ed Bispham came to the rescue with exactly the evidence I needed. Matthew Leigh and John Penney have both helped me with aspects of the argument and presentation, and enlightened me in the process. None of these scholars, needless to say, shares responsibility for the shortcomings of what follows. The paper originated as a lecture to that most exacting and rewarding audience, the students of the JACT Latin Summer School.