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.

- W.B. Yeats, The Second Coming (1919)