The speaker retells a story from Greek mythology, the rape of the girl Leda by the god Zeus, who had assumed the form of a swan. Leda felt a sudden blow, with the “great wings” of the swan still beating above her. Her thighs were caressed by “the dark webs,” and the nape of her neck was caught in his bill; he held “her helpless breast upon his breast.” How, the speaker asks, could Leda’s “terrified vague fingers” push the feathered glory of the swan from between her thighs? And how could her body help but feel “the strange heart beating where it lies”? A shudder in the loins engenders “The broken wall, the burning roof and tower, and Agamemnon dead.” The speaker wonders whether Leda, caught up by the swan and “mastered by the brute blood of the air,” assumed his knowledge as well as his power “Before the indifferent beak could let her drop.”
“Leda and the Swan” is a sonnet, a traditional fourteen-line poem in iambic pentameter. The structure of this sonnet is Petrarchan with a clear separation between the first eight lines (the “octave”) and the final six (the “sestet”), the dividing line being the moment of ejaculation—the “shudder in the loins.” The rhyme scheme of the sonnet is ABAB CDCD EFGEFG.
Like “The Second Coming,” “Leda and the Swan” describes a moment that represented a change of era in Yeats’s historical model of gyres, which he offers in A Vision, his mystical theory of the universe. But where “The Second Coming” represents (in Yeats’s conception) the end of modern history, “Leda and the Swan” represents something like its beginning; as Yeats understands it, the “history” of Leda is that, raped by the god Zeus in the form of a swan, she laid eggs, which hatched into Clytemnestra and Helen and the war-gods Castor and Polydeuces—and thereby brought about the Trojan War (“The broken wall, the burning roof and tower, / And Agamemnon dead”). The details of the story of the Trojan War are quite elaborate: briefly, the Greek Helen, the most beautiful woman in the world, was kidnapped by the Trojans, so the Greeks besieged the city of Troy; after the war, Clytemnestra, the wife of the Greek leader Agamemnon, had her husband murdered. Here, however, it is important to know only the war’s lasting impact: it brought about the end of the ancient mythological era and the birth of modern history.
Also like “The Second Coming,” “Leda and the Swan” is valuable more for its powerful and evocative language—which manages to imagine vividly such a bizarre phenomenon as a girl’s rape by a massive swan—than for its place in Yeats’s occult history of the world. As an aesthetic experience, the sonnet is remarkable; Yeats combines words indicating powerful action (sudden blow, beating, staggering, beating, shudder, mastered, burning, mastered) with adjectives and descriptive words that indicate Leda’s weakness and helplessness (caressed, helpless, terrified, vague, loosening), thus increasing the sensory impact of the poem.