[51] Diogenes (ix. 49) uses the same phrase in regard to the spurious works ascribed to Demokritus, τὰ δ’ ὁμολογουμένως ἐστὶν ἀλλότρια. And I believe that he means the same thing by it: that the works alluded to were not recognised in the Alexandrine library as belonging to Demokritus, and were accordingly excluded from the tetralogies (of Demokritus) prepared by Thrasyllus.
Thrasyllus did not follow an internal sentiment of his own in rejecting dialogues as spurious.
If Thrasyllus and the others did not proceed upon this evidence in rejecting the ten dialogues, and did not find in them any marks of time such as to exclude the supposition of Platonic authorship — they decided upon what is called internal evidence: a critical sentiment, which satisfied them that these dialogues did not possess the Platonic character, style, manner, doctrines, merits, &c. Now I think it highly improbable that Thrasyllus could have proceeded upon any such sentiment. For when we survey the catalogue of works which he recognised as genuine, we see that it includes the widest diversity of style, manner, doctrine, purpose, and merits: that the disparate epithets, which he justly applies to discriminate the various dialogues, cannot be generalised so as to leave any intelligible “Platonic character” common to all. Now since Thrasyllus reckoned among the genuine works of Plato, compositions so unlike, and so unequal in merit, as the Republic, Protagoras, Gorgias, Lysis, Parmenidês, Symposion, Philêbus, Menexenus, Leges, Epinomis, Hipparchus, Minos, Theagês, Epistolæ, &c., not to mention a composition obviously unfinished, such as the Kritias — he could have little scruple in believing that Plato also composed the Eryxias, Sisyphus, Demodokus, and Halkyon. These last-mentioned dialogues still exist, and can be appreciated.[52] Allowing, for the sake of argument, that we are entitled to assume our own sense of worth as a test of what is really Plato’s composition, it is impossible to deny, that if these dialogues are not worthy of the author of Republic and Protagoras, they are at least worthy of the author of the Leges, Epinomis, Hipparchus, Minos, &c. Accordingly, if the internal sentiment of Thrasyllus did not lead him to reject these last four, neither would it lead him to reject the Eryxias, Sisyphus, and Halkyon. I conclude therefore that if he, and all the other critics whom Diogenes esteemed, agreed in rejecting the ten dialogues as spurious — their verdict depended not upon any internal sentiment, but upon the authority of the Alexandrine library.[53]
[52] The Axiochus, Eryxias, Sisyphus, and Demodokus, are printed as Apocrypha annexed to most editions of Plato, together with two other dialogues entitled De Justo and De Virtute. The Halkyon has generally appeared among the works of Lucian, but K. F. Hermann has recently printed it in his edition of Plato among the Platonic Apocrypha.
The Axiochus contains a mark of time (the mention of Ἀκαδημία and Λυκεῖον, p. 367), as F. A. Wolf has observed, proving that it was not composed until the Platonic and Peripatetic schools were both of them in full establishment at Athens — that is, certainly after the death of Plato, and probably after the death of Aristotle. It is possible that Thrasyllus may have proceeded upon this evidence of time, at least as collateral proof, in pronouncing the dialogue not to be the work of Plato. The other four dialogues contain no similar evidence of date.
Favorinus affirmed that Halkyon was the work of an author named Leon.
Some said (Diog. L. iii. 37) that Philippus of Opus, one of the disciples of Plato, transcribed the Leges, which were on waxen tablets (ἐν κηρῷ), and that the Epinomis was his work (τούτου δὲ καὶ τὴν Ἐπινομίδα φασὶν εἶναι). It was probably the work of Philippus only in the sense in which the Leges were his work — that he made a fair and durable copy of parts of it from the wax. Thrasyllus admitted it with the rest as Platonic.
[53] Mullach (Democr. Fragm. p. 100) accuses Thrasyllus of an entire want of critical sentiment, and pronounces his catalogue to be altogether without value as an evidence of genuine Platonic works — because Thrasyllus admits many dialogues, “quos doctorum nostri sæculi virorum acumen è librorum Platonicorum numero exemit”.
This observation exactly illustrates the conclusion which I desire to bring out. I admit that Thrasyllus had a critical sentiment different from that of the modern Platonic commentators; but I believe that in the present case he proceeded upon other evidence — recognition by the Alexandrine library. My difference with Mullach is, that I consider this recognition (in a question of genuine or spurious) as more trustworthy evidence than the critical sentiment of modern literati.