Yeats believed in the cyclical nature of the world, an interest that appeared thematically in his poems concerning life, death, and the repetition of history. In particular, he thought history cycled through a pattern every 2,000 years. His beliefs appear in the wording of “The Second Coming” and in his letter to a friend, in which he suggested that the poem predicted the Nazis’ rise to power. While Yeats didn’t specifically know that another world war was coming, he felt that the cycle was perpetuating and would culminate in some dark disaster.

Yeats first suggests the beginning of a cycle in the poem’s first few lines, with a falcon circling like a gyre. A gyre is a kind of vortex, often the swirling of an ocean tide. Yeats uses the gyre image to describe several spiritual phenomena that he and Georgie Hyde-Lees saw and experienced, and he uses it in reference to the nature of history in his book, A Vision:

Then the gyre develops a new coherence in the external scene; and violent men, each master of some generalization, arise one after another: Napoleon, a man of the 20th Phase in the historical 21st […] typical of all.