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: a waste of desert sand;
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
Wind 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?
-- William Butler Yeats (1920)
By the way, there's no evidence that Yeats ever said the above, about himself or anyone else. Quotation sites on the internet can be fun to peruse, but unless they include specific references to printed works, caveat emptor. Still, it is a nice antidote to the terror inspired by the poem.
Here's a nice reading of the poem:
For a more traditional Saint Patrick's Day tribute, there's always this: