Yeats's sense of his own implication in history, well, it's something that we see in the intensive, stylistic transformations that his writing undergoes.

就是叶芝对历史的想法，这就是我们看到的，他的彻底的风格上的改变,他的写作风格的改变。

耶鲁公开课 - 现代诗歌课程节选