Line 1: The "gyre" is an important recurring symbol in Yeats’s poetry. Technically, it stands from the alternation between two historical cycles: one characterized by order and growth, the other by chaos and decay. It’s comparable to the Chinese concepts of Yin and Yang. Yeats wrote a poem called "The Gyres" in his collection The Tower, but even there it’s still pretty confusing. Fortunately, all that philosophical background isn’t essential to the poem.