"The Wild Swans at Coole," by William Butler Yeats, may seem at first glance to be a traditional poem about the beauty of nature.  Yeats notes the trees "in their autumn beauty," and the "mysterious, beautiful" swans who "delight men's eyes."

Upon deeper inspection, however, Yeats's poem is pessimistic and thoroughly modern.  The poet's heart has grown "sore" and old, a common plight of the existensialist who sees no chance of winning man's battle with the world. 

Although he has been watching the swans for nineteen years, he feels alienated from them when the swans fly away from him:

I saw...

All suddenly mount

And scatter wheeling great broken rings

Upon their clamorous wings.

The poet seems to envy the swans who paddle together in "companionable streams," while he travels alone, having long since given up dreams of "passion or conquest."