51-53. AGAMEMNONA ... THEBAS. The two great cycles of Greek heroic mythology. The same conjunction at Am III xii 15-16 'cum Thebae, cum Troia foret, cum Caesaris acta, / ingenium mouit sola Corinna meum' and Tr II 317-20 'cur non Argolicis potius quae concidit armis / uexata est iterum carmine Troia meo? / cur tacui Thebas et uulnera mutua fratrum / et septem portas sub duce quamque suo'; compare as well Prop II i 21 '[canerem ...] nec ueteres Thebas nec Pergama, nomen Homeri'. Lucretius, arguing that the world was created at a definite moment, wrote 'cur supera ['before'] bellum Thebanum et funera Troiae / non alias alii quoque res cecinere poetae?' (V 326-27).
52. QVISQVIS CONTRA VEL SIMVL ARMA TVLIT. The leaders of the Greeks and Trojans.
The line's structure parallels 54 'quicquid post haec, quicquid et ante fuit'. Both are conspicuous by their lack of adornment.
55. DI QVOQVE CARMINIBVS, SI FAS EST DICERE, FIVNT. This is possibly a reference to Herodotus II 53, where Herodotus says that Homer and Hesiod established the Greek pantheon; for Ovid's borrowings from Herodotus, see at iii 37 opulentia Croesi ([p 189]). The same idea previously in Xenophanes (fr. 11 Diels).
The line looks ahead to 63-64 'et modo, Caesar, auum, quem uirtus addidit astris, / sacrarunt aliqua carmina parte tuum'.
55. SI FAS EST DICERE. Ovid here apologizes for the shocking statement he is making. Up to this point poetry has helped give lasting fame to what was already a fact, but here poetry is actually making something happen (or appear to happen). At Am III xii 21-40 Ovid similarly describes how poets created the myths.
57-64. Ovid follows the same sequence in the Metamorphoses, describing the separation of Chaos at I 5-31, the attack of the Giants at I 151-55, Bacchus' conquest of India at IV 20-21 & 605-6, and Hercules' capture of Oechalia at IX 136; he foretells Augustus' apotheosis at XV 868-70. Professor R. J. Tarrant points out that these lines may well be referring specifically to the earlier poem.
57-58. SIC CHAOS EX ILLA NATVRAE MOLE PRIORIS / DIGESTVM PARTES SCIMVS HABERE SVAS. 'Thus we know Chaos now has its divisions after having been arranged in order from the famous mass that was its previous nature'. Ovid describes the separation of the elements at Met I 25-31 and Fast I 103-10; see also Ecl VI 31-36.
I take illa ('famous') to refer to the familiarity through the poets and philosophers of the notion of the separation of Chaos into the four elements. Alternatively, Professor A. Dalzell points out to me that illa could have a pejorative sense.
58. DIGESTVM. 'Separated'. At Met I 7 Ovid calls Chaos 'rudis indigestaque moles'.