Written 100 years ago, Yeats’s poem has been absorbed into the cultural bloodstream from Chinua Achebe to The Sopranos, Joan Didion to Gordon Gecko. Why is it such a touchstone in times of chaos?

n April 1936, three years before his death, WB Yeats received a letter from the writer and activist Ethel Mannin. The 70-year-old Yeats was a Nobel prize-winning poet of immense stature and influence, not to mention Mannin’s former lover, and she asked him to join a campaign to free a German pacifist incarcerated by the Nazis. Yeats responded instead with a reading recommendation: “If you have my poems by you, look up a poem called ‘The Second Coming’,” he wrote. “It was written some sixteen or seventeen years ago & foretold what is happening. I have written of the same thing again & again since. This will seem little to you with your strong practical sense for it takes fifty years for a poet’s weapons to influence the issue.”