On the other hand, our author (Section XIII) quotes the critical ideas of “Ammonius and his school,” as to the debt of Plato to Homer. Now the historical Longinus was a friend of the Neoplatonist teacher (not writer), Ammonius Saccas. If we could be sure that the Ammonius of the Treatise was this Ammonius, the question would be settled in favour of the late date. Our author would be that Longinus who inspired Zenobia to resist Aurelian, and who perished under his revenge. But Ammonius is not a very uncommon name, and we have no reason to suppose that the Neoplatonist Ammonius busied himself with the literary criticism of Homer and Plato. There was, among others, an Egyptian Ammonius, the tutor of Plutarch.
These are the mass of the arguments on both sides. M. Egger sums them up thus: “After carefully examining the tradition of the MSS., and the one very late testimony in favour of Longinus, I hesitated for long as to the date of this precious work. In 1854 M. Vaucher[1] inclined me to believe that Plutarch was the author.[2] All seems to concur towards the opinion that, if not Plutarch, at least one of his contemporaries wrote the most
