The text used in this volume is based on Bekker’s, but in a sense which may be thought Pickwickian and must be defined. “Based on” means that, to the best of my knowledge, every departure from Bekker has been noted and its authority acknowledged. The departures are many, for Bekker’s text is faulty and it would have been contrary to the principles of this series to ignore the improvements introduced in the excellent edition of Mr. D. J. Allan, which appeared most opportunely in the Oxford Classical Texts while this translation was in preparation. I have availed myself extensively of the information contained in his critical apparatus. I have also used the text and German translation of C. Prantl (Leipzig, 1854), but his readings agree to a large extent with those of Bekker, and his own alterations are not always an improvement. I have only occasionally cited him by name.
My greatest debt is to the translation of this treatise by J. L. Stocks in the Oxford translation of Aristotle. This was a pioneer work, and has set an example of true scholarship and philosophic understanding which it is bold indeed to emulate. Others can speak better of the gap which his early death has left in the intellectual life of England, but I would record a sense of