Turning and turning in the widening gyre The falcon cannot hear the falconer; Things fall apart; the centre cannot hold; Mere anarchy is loosed upon the world, The blood-dimmed tide is loosed, and everywhere The ceremony of innocence is drowned; The best lack all conviction, while the worst Are full of passionate intensity.

Per wiki:

The poem is also connected to the 1918–1919 flu pandemic: In the weeks preceding Yeats's writing of the poem, his pregnant wife Georgie Hyde-Lees caught the virus and was very close to death. The highest death rates of the pandemic were among pregnant women—in some areas, they had up to a 70 percent death rate. While his wife was convalescing, he wrote "The Second Coming".