Butler writes in prose and Mitchell in verse, and the difference is immediately visible in the opening lines. Butler's "Sing, O goddess, the anger of Achilles son of Peleus" is a single continuous sentence that moves through the invocation briskly and without pause. Mitchell breaks the same content into lines that carry a slight rhythmic pulse: "The rage of Achilles — sing it now, goddess, sing through me." Butler's diction drifts toward the archaic: "man after my own heart," "smite him in close combat," "villain incarnate." Mitchell stays in contemporary English throughout, and in Book 21 replaces Butler's formal "Why should you whine in this way?" with the plainer "Why all this moaning about it?" The register gap is consistent across all five passages. Butler published in 1898 and prioritizes clear, readable prose that moves fast and stays close to the narrative sequence of the Greek. He sometimes compresses: in Book 9 he cuts Achilles' speech to its essential choice, dropping context that Mitchell keeps, such as the detail that Thetis names two possible fates. Mitchell, writing over a century later, is attentive to the spoken quality of the text. His version of Book 21 gives Achilles a conversational directness ("So courage, my friend") that reads as something meant to be heard aloud. Butler's prose is easier to read quickly and costs nothing to access, being in the public domain. Mitchell's line breaks slow a reader down and keep the poem's repetitions and pauses visible on the page.
Sing, O goddess, the anger of Achilles son of Peleus, that brought countless ills upon the Achaeans. Many a brave soul did it send hurrying down to Hades, and many a hero did it yield a prey to dogs and vultures, for so were the counsels of Jove fulfilled from the day on which the son of Atreus, king of men, and great Achilles, first fell out with one another.
The rage of Achilles—sing it now, goddess, sing through me
the deadly rage that caused the Achaeans such grief
and hurled down to Hades the souls of so many fighters,
leaving their naked flesh to be eaten by dogs
and carrion birds, as the will of Zeus was accomplished.
Begin at the time when bitter words first divided
that king of men, Agamemnon, and godlike Achilles.