From a New York Times column by David French headlined “Promising Signs for Free Speech on Campus”:

William Butler Yeats’s “The Second Coming” has been called the most plundered poem in the English language, and it’s easy to see why. The poem, written in the immediate aftermath of World War I and during the height of the Russian Civil War, vividly captures the feeling that events are sliding out of control. Three lines in particular resonate in troubled times. “Things fall apart; the center cannot hold,” writes Yeats. “The best lack all conviction, while the worst / Are full of passionate intensity.”