Lately there has been talk of the "narrative arc" of chapbooks & poetry collections. Some eschew this tendency on the part of other poets while others laud the benefits of the poems in a manuscript to "hold together". I'm not sure that any poem written by the same author can be anything but a part of a "narrative arc". After all whatever one writes is but a facet of the mindset of that author. If we "see things as we are" can anything that is produced by our cognitive mindset be that different from whatever else we wrote say in the last few years that it took for us to put a MS together (barring some life-changing occurrence)?
Yes cognitive mindsets do evolve and change as life's experiences change, but certain socio-cultural variables (which inevitably define us) will always be constant in our lives. These variables are unique in each and every person. That is why one voice can never fully echo another. This is also why I must reluctantly side with the school of thought that thinks that deliberately manipulating a manuscript to more closely appear that it follows a "narrative arc" is redundant. There already is a "narrative arc" in place and that is the narrative of the poet's existence that is transmitted to us via the objectification of their poems.