A tentative interpretation of Stevens's Sunday Morning

I posted about a year ago on the poetry of William Carlos Williams, comparing him, mostly favorably, to Wallace Stevens - noting that I appreciated WCW a lot more when I was young (college, grad school) probably because his poetry was more accessible, at least on a superficial level (Paterson is not so accessible, on any level) and found WS to be in the "dead end" of language poetry, I noted in the post, that wins prizes and is published in the NYer but that nobody reads, but also noted that his work requires multiple readings and becomes more profound, if not more accessible, following many readings. (Whereas WCW you can get - or least get something out of it - on first glance.) I guess I've been reading Stevens's major poems on and off for 50 years (!) and have probably read Sunday Morning 20 times or so and am still just starting to get it - whether that says something about the poem or about me I'm not sure. Even on first reading you should be able to see that WS is a master of blank verse (iambic pentameter, the most classic meter for the English language) and that some of his embedded sentences are beautiful and elegaic. You'll also see some recurring imagery - especially in the use of birds, a trope throughout his work and line cast back across the history of Englsh poetry, to Keats and Shelley of course but also the Shakespeare himself (who had many aviary references throughout the canon). But what is Sunday Morning about? A few observations: It has taken me years to see this, but the poem is in some ways an argument or debate between the poet and the "lady" depicted in the poem. As it opens she is enjoying the beauty and serenity of a Sunday morning, but she also recognizes that she's skipping out on church. Over the the dozen or so stanzas she tries to build a case that appreciation of nature's beauty and of art is a form of devotion; the poet - or the exterior voice - begins to question that and suggests that our "blood" demands a greater sacrifice and engagement than mere passive appreciation (I honestly have no idea what WS means when he says "blood"; several passages in this poem need a lifetime's devotion from a critic such as Helen Vendler and Ed Mendelson - and even then they are obscure or opaque). The woman thinks that only in nature can seh find perfection, but the poet's voice says that beauty in nature occurs only because things change, decay, and die (Death is the mother of beauty - which is stated twice in the poem). But what bout in paradise, the woman asks, and the voice says that yes, in paradise, too, there is death. That we get to the strange penultimate stanza in which a group of men seem to be engaging in some kind of pagan form of worship (why only men? and what's w/ the blood references again?) - but that seems to be a false idolization, and in the final stanza the woman again appreciates the beauty of nature but recognizes its transience, as the flock of birds descends to darkness "on extended wings" - so in a sense we have completed a full day's cycle, beginning w/ a bright morning and at the end descending to darkness, perhaps like life (or like humanity?).