Yeats: Old Man and Young

“An aged man is but a paltry thing, a tattered coat upon a stick, unless / soul clap its hands and sing, and louder sing / for every tatter in its mortal dress.” 
W.B. Yeats, "Sailing to Byzantium"

***

As a young man, Yeats wrote:

The Second Coming (1919)

First published in The Dial (November 1920) and The Nation (6 November 1920), later publisehed in Michael Robartes and the Dancer (1921) - Online text with some notes on variant editions - online text and notes

• 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: 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?
  ***
  
  http://en.wikipedia.org/wiki/W._B._Yeats