The didactic (could it be?) poem by Bernstein is interesting, as is the essay by Graves and Riding, but just a few words about them.
Naturally, or unnaturally to be more accurate, language and world never meet, so it is "true" that the "ideal" modernist poem would not refer to nor need confirmation re relativity towards another world than its own.
However, the problem, at least as I see it, is that language, the new language-event, the creature in itself, however framed and referenced always will reference a world that while self-referential nevertheless refers to an image-idea of a world for which and from which it derived. In other words, while language never reaches a referent it always has a signified, a reference to such.
So, the use of their word "subject," for instance, really means "object," doesn't it? The "dead" idea of a subject; but subject is interior? or does it mean subject as in object, that is, what something is about?
Funny, but if you read some of the poems of Riding and Graves you will find that they must- there is no other recourse in language (because it has "meaning") always mention, refer to a subject that is both in the poem and something thought of (meant- referent) outside of the poem): example, "dream" or "the world and I" or in "due form," whatever. In short, though the modernist poem may be referring to itself and language and events within the poem alone, it cannot help but, it cannot separate itself from what I take, perhaps incorrectly, as the basis of language, its reference, even if abstractly and not precisely, to things. Though each word may have only a sound mental-image and a meaning ( a reference) and no referent, nonetheless all words seem to yearn ( is that not what Riding writes in The World and I?) for such a relationship.
As to calling those who wrote high modernism, Pound for instance, writers of dead poems, if there was any fairness in the evaluation and not an attempt to usurp the time to themselves and their writing- think of pan here and how he became the devil with the advent of christianity- well, they would merely apply their own standards, as would Bernstein, and show that in Pound's/Eliot's poems, whatever the prejudice they claim existed in these poets, they would show, repeat, how the poems worked as poems only can work, that is, just the way they say they do and that these high modernists' works were new word-thought events, too,did not refer to a separate subject, etc.
As to Stevens, why yes, indeed, he makes it quite clear that human creation is not natural but brings nature to order, as in In Jar and The Idea of Order, and The Blue Guitar, et al. But just look at those words- are they not sounds, i.e., mental-images, with reference and meaning, though lacking in a referent (an outside object; words as mere approximations always yearning for their imaginary solids).
So, interesting quotes indeed, Philip, and interesting thoughts, and thanks for that.