William Butler Yeats

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.

Surely some revelation is at hand;
Surely the Second Coming is at hand.   
The Second Coming! Hardly are those words out   
When a vast image out of Spiritus Mundi
Troubles my sight: somewhere in sands of the desert   
A shape with lion body and the head of a man,   
A gaze blank and pitiless as the sun,   
Is moving its slow thighs, while all about it   
Reel shadows of the indignant desert birds.   
The darkness drops again; but now I know   
That twenty centuries of stony sleep
Were vexed to nightmare by a rocking cradle,   
And what rough beast, its hour come round at last,   
Slouches towards Bethlehem to be born?