That Diodorus (or the copyist) has here mistaken Thebans for Athenians, appears to me, on the following grounds:—
1. Whoever reads attentively the oration delivered by Demosthenes in the Athenian assembly (about ten years after this period) respecting the propriety of sending an armed force to defend Megalopolis against the threats of Sparta—will see, I think, that Athens can never before have sent any military assistance to Megalopolis. Both the arguments which Demosthenes urges, and those which he combats as having been urged by opponents, exclude the reality of any such previous proceeding.
2. Even at the time when the above-mentioned oration was delivered, the Megalopolitans were still (compare Diodorus, xvi, 39) under special alliance with, and guardianship of, Thebes—though the latter had then been so much weakened by the Sacred War and other causes, that it seemed doubtful whether she could give them complete protection against Sparta. But in the year next after the battle of Mantinea, the alliance between Megalopolis and Thebes, as well as the hostility between Megalopolis and Athens, was still fresher and more intimate. The Thebans (then in unimpaired power), who had fought for them in the preceding year,—not the Athenians, who had fought against them,—would be the persons invoked for aid to Megalopolis; nor had any positive reverses as yet occurred to disable the Thebans from furnishing aid.
3. Lastly, Pammenes is a Theban general, friend of Epaminondas. He is mentioned as such not only by Diodorus himself in another place (xvi, 34), but also by Pausanias (viii, 27, 2), as the general who had been sent to watch over the building of Megalopolis, by Plutarch (Plutarch, Pelopidas, c. 26; Plutarch, Reipub. Gerend. Præcept. p. 805 F.), and by Polyænus (v, 16, 3). We find a private Athenian citizen named Pammenes, a goldsmith, mentioned in the oration of Demosthenes against Meidias (s. 31. p. 521); but no Athenian officer or public man of that time so named.
Upon these grounds, I cannot but feel convinced that Pammenes and his troops were Thebans, and not Athenians.
I am happy to find myself in concurrence with Dr. Thirlwall on this point (Hist. Gr. vol. v, ch. xliii, p. 368 note).
[782] See Isokrates, Orat. vi, (Archidamus) s. 85-93.
[783] Isokrates, Or. vi, (Archid.) s. 73.
[784] Cornelius Nepos has given a biography of Datames at some length, recounting his military exploits and stratagems. He places Datames, in point of military talent, above all barbari, except Hamilcar Barca and Hannibal (c. 1). Polyænus also (vii, 29) recounts several memorable proceedings of the same chief. Compare too Diodorus, xv, 91; and Xen. Cyropæd. viii, 8, 4.
We cannot make out with any certainty either the history, or the chronology, of Datames. His exploits seem to belong to the last ten years of Artaxerxes Mnemon, and his death seems to have taken place a little before the death of that prince; which last event is to be assigned to 359-358 B.C. See Mr. Fynes Clinton, Fast. Hell. ch. 18. p. 316, Appendix.