The following passage is adapted from a scholarly paper that examines Yeats’s poem “The Tower.”
The Tower’s three parts correspond to three stages of life, or three modes of relating to the world, but not in a sense as simple as youth, adulthood and old age. Rather, the first and third parts—or the first and third poems in a three-poem sequence—chart the internal experiences of an accelerating mind within a decelerating body. The second part is a more external reminiscence, passing elegiacally over the lore of the land. The dying poet is taking a nostalgic survey of his works. The first and third parts take place within a dreaming mind, while the second takes place within the dream.
If we think of this poem as a ceremony, the first part senses that the end is near, but is not ready to face it; the second part is a preparation ritual, and the third part is readiness and passes into nothing. If this passing is to have any meaning, the poet must propel himself enthusiastically into the next world rather than fall, withered and bedraggled, out of this one. To do so, he must find the memories in which he was most alive, maybe the ones that still hurt the most. These moments were truly his, and so are truly his to leave behind.