What is the purpose of "The Lives of the Heart"?

This poem is surprising in terms of its many references,
which as part of the development are not truly predictable. That is just one of the
poem’s surprises. Hirshfield calls on her readers to follow her through many avenues and
byways, finally to reach a conclusion in the depths of feeling that are usually
associated with the affections and the heart. Understanding the many byways and special
tours on the road to Hirshfield’s conclusion requires great alertness and imagination.
It is one of the delights of poetry to not just take us down familiar roads, but to
bring us down roads that we think we might have taken but allow us to experience them in
new ways or to see things differently. This is one powerful poem about the
heart.