In discussing the Platonic Canon, I have already declared that I consider these grounds of rejection to be unsafe and misleading. Such judgment is farther confirmed, when we observe the consequences to which they would conduct in regard to the Aristotelian Canon. In fact, we must learn to admit among genuine works, both of Plato and Aristotle, great diversity in subject, in style, and in excellence. I see no ground for distrusting the Catalogue given by Diogenes, as being in general an enumeration of works really composed by Aristotle. These works must have been lodged in some great library--probably the Alexandrine--where they were seen and counted, and the titles of them enrolled by some one or more among the _literati_, with a specification of the sum total obtained on adding together the lines contained in each.[17] I do not deny the probability, that, in regard to some, the librarians may have been imposed upon, and that pseudo-Aristotelian works may have been admitted; but whether such was partially the fact or not, the general goodness of the Catalogue seems to me unimpeachable. As to the author of it, the most admissible conjecture seems that of Brandis and others, recently adopted and advocated by Heitz: that the Catalogue owes its origin to one of the Alexandrine _literati_; probably to Hermippus of Smyrna, a lettered man and a pupil of Kallimachus at Alexandria, between 240-210 B.C.. Diogenes does not indeed tell us from whom he borrowed the Catalogue; but in his life of Aristotle, he more than once cites Hermippus, as having treated of Aristotle and his biography in a work of some extent; and we know from other sources that Hermippus had devoted much attention to Aristotle as well as to other philosophers. If Hermippus be the author of this Catalogue, it must have been drawn up about the same time that the Byzantine Aristophanes arranged the dialogues of Plato. Probably, indeed, Kallimachus the chief librarian, had prepared the way for both of them. We know that he had drawn up comprehensive tables, including, not only the principal orators and dramatists, with an enumeration of their discourses and dramas, but also various miscellaneous authors, with the titles of their works. We know, farther, that he noticed Demokritus and Eudoxus, and we may feel assured that, in a scheme thus large, he would not omit Plato or Aristotle, the two great founders of the first philosophical schools, nor the specification of the works of each contained in the Alexandrine library.[18] Heitz supposes that Hermippus was the author of most of the catalogues (not merely of Aristotle, but also of other philosophers) given by Diogenes;[19] yet that nevertheless Diogenes himself had no direct acquaintance with the works of Hermippus, but copied these catalogues at second-hand from some later author, probably Favorinus. This last supposition is noway made out.