Diodorus had before him a very different account. He affirms that Alexander both combined and ordered the assault—that the Thebans behaved like bold and desperate men, resisting obstinately and for a long time—that the slaughter afterwards was committed by the general body of the assailants; the Bœotian allies being doubtless conspicuous among them. Diodorus gives this account at some length, and with his customary rhetorical amplifications. Plutarch and Justin are more brief; but coincide in the same general view, and not in that of Arrian. Polyænus again (iv. 3 12) gives something different from all.
To me it appears that the narrative of Diodorus is (in its basis, and striking off rhetorical amplifications) more credible than that of Arrian. Admitting the attack made by Perdikkas, I conceive it to have been a portion of the general plan of Alexander. I cannot think it probable that Perdikkas attacked without orders, or that Thebes was captured with little resistance. It was captured by one assault (Æschines adv. Ktesiph. p. 524), but by an assault well-combined and stoutly contested—not by one begun without preparation or order, and successful after hardly any resistance. Alexander, after having offered what he thought liberal terms, was not the man to shrink from carrying his point by force; nor would the Thebans have refused those terms, unless their minds had been made up for strenuous and desperate defence, without hope of ultimate success.
What authority Diodorus followed, we do not know. He may have followed Kleitarchus, a contemporary and an Æolian, who must have had good means of information respecting such an event as the capture of Thebes (see Geier, Alexandri M. Historiarum Scriptores ætate suppares, Leips. 1844, p. 6-152; and Vossius, De Historicis Græcis. i. x. p. 90, ed. Westermann). I have due respect for the authority of Ptolemy, but I cannot go along with Geier and other critics who set aside all other witnesses, even contemporary, respecting Alexander, as worthy of little credit, unless where such witnesses are confirmed by Ptolemy or Aristobulus. We must remember that Ptolemy did not compose his book until after he became king of Egypt, in 306 B. C.; nor indeed until after the battle of Ipsus in 301, according to Geier (p. 1); at least twenty-nine years after the sack of Thebes. Moreover, Ptolemy was not ashamed of what Geier calls (p. 11) the “pious fraud” of announcing, that two speaking serpents conducted the army of Alexander to the holy precinct of Zeus Ammon (Arrian, iii. 3). Lastly, it will be found that the depositions which are found in other historians, but not in Ptolemy and Aristobulus, relate principally to matters discreditable to Alexander. That Ptolemy and Aristobulus omitted, is in my judgment far more probable, than that other historians invented. Admiring biographers would easily excuse themselves for refusing to proclaim to the world such acts as the massacre of the Branchidæ, or the dragging of the wounded Batiz at Gaza.
[92] Arrian, i. 8; Diodor. xvii. 12, 13.
[93] Diodorus (xvii. 14) and Plutarch (Alexand. 11) agree in giving the totals of 6000 and 30,000.
[94] Arrian, i. 9; Diodor. xvii. 14.
[95] Justin, xi. 4.
[96] Diodor. xvii. 14; Justin, xi. 4: “pretium non ex ementium commodo, sed ex inimicorum odio extenditur.”
[97] Arrian, i. 9, 13. Τοῖς δὲ μετασχοῦσι τοῦ ἔργου ξυμμάχοις, οἷς δὴ καὶ ἐπέτρεψεν Ἀλέξανδρος τὰ κατὰ τὰς Θήβας διαθεῖναι, ἔδοξε, etc.
[98] Arrian, i. 9, 10. He informs us (i. 9, 12) that there were many previous portents which foreshadowed this ruin: Diodorus (xvii. 10) on the contrary, enumerates many previous signs, all tending to encourage the Thebans.