This study began as a paper. It got out of hand. It had help doing that. Oswaldo Chateaubriand, Ronald Haver, Paul Horwich, Bernie Katz, Norman Kretzmann, Stanley Martens, Stephen Pink, Michael Stokes, Eleanor Stump, Bill Ulrich, Celia Wolf, and a lot of other people questioned or criticized or helped reformulate one or another of the arguments and interpretations along the way. In spite of (maybe partly because of) their efforts, the book is full of mistakes. At least, induction over previous drafts indicates that irresistibly. But I do not, right now, know of any particular mistakes. All but a couple of the translations are mine (the exceptions are noted). That is not because existing translations are bad, but because some uniformity was essential. The translations often make unpleasant reading. So, often, does Aristotle; I have tried to be literal. A text and translation of the passage on which the book centers is in Appendix III. Footnotes cite literature by author and (sometimes abbreviated) title. Details are in the bibliography. I do not profess to have covered all the literature. An enormous amount of editorial work was done by Margaret Mundy. She was not able to undo the errors that remain. In particular, the footnotes are often numbered oddly: '4', '4a', '4b', etc.