…the poetic process as revealed by Poe and the symbolists was the unexpected and unintentional means of reestablishing the basis of Catholic humanism.
(Catholic Humanism and Modern Letters, 1954)

It was the symbolist poets who began the study of effects minus causes. This is a technique indispensable to the developing of perception and the by-passing of concepts. (McLuhan to Jim Davey, March 22, 1971)

T.S. Eliot’s 1948 lecture, ‘From Poe to Valéry’, was published in print in The Hudson Review in 1949 (Vol. 2, No. 3). McLuhan paid close attention to it, of course. He had been intensely interested in Eliot since his first months in Cambridge in 1934. A letter to his family from Dec 6, 1934 records:

Of late I have been wayfaring among the work of T.S. Eliot. He is easily the greatest modern poet, and just how great he is remains to be seen, because he has not produced his best yet. However the poems I am reading [Poems 1909-1925] have the unmistakable character of greatness. They transform, and diffuse and recoalesce the commonest every day occurrences of 20th cent. city life till one begins to see double indeed — the extremely unthinkable character, the glory and the horror of the reality in life yet, to all save the seer, [obscured] behind [the surface of] life, is miraculously suggested. (Eliot is an anglo-Catholic, a theologian and philosopher and one of the best critics who ever wrote in English.) Now there is something ineffably exciting in reading a man, a genius and a poet, who has by the same stages, in face of the same  circumstances (he is an American), come to the same point of view concerning the nature of religion and Christianity, the interpretation of history, and the value of industrialism. (Letters 41)

Fifteen years later, when ‘From Poe to Valéry’ was published, McLuhan was still preoccupied with Eliot. As Hugh Kenner later recalled:

Marshall, at that time pretty much a New Critic, believed with F. R. Leavis that the one major poet of our time was Eliot. (…) The passion (…) with which we two (…) studied Eliot! We penciled notes on the yellow postwar paper of a Faber Four Quartets…¹

McLuhan also had an established interest in Poe. He had published two early papers on him,² the second after he had his notice directed to Poe’s Maelstrom in 1946 by his friend, Cleanth Brooks, in a way that would continue to fascinate him for the rest of his life.³

Furthermore, in just this 1948-1949 period when Eliot’s ‘Poe to Valéry’ lecture was delivered and then published, McLuhan and Kenner were working on a book on Eliot. Indeed, Kenner published an essay on Eliot, ‘Eliot’s Moral Dialectic’, in the same issue of The Hudson Review that featured Eliot’s lecture.⁴ And on his side, McLuhan published an essay on Eliot, and a review of eleven books on Eliot, in Renascence magazine in 1949 and 1950.⁵

Eliot’s lecture played an important role in McLuhan’s second conversion by reinforcing his attention to two issues: (1) the relationship of the modern English-American tradition in letters (especially Yeats, Pound, Joyce, Eliot and Lewis) to the French symbolist tradition from Baudelaire to Valéry; (2) the critical importance of the process of composition to modern art and science (indeed to all perception of any kind).⁶

Eliot’s essay highlighted the second of these points and in doing so illustrated also the first:

in the course of an introduction [to his translation of Poe’s tales and essays] (…) Baudelaire lets fall one remark indicative of an aesthetic that brings us to Valéry: “[Poe] believed, (…) true poet that he was, that the goal of poetry is of the same nature as its principle, and that it should have nothing in view but itself. A poem does not say something — it is something.”

That “poetry (…) should have nothing in view but itself” is repeated in the dictum that “a poem does not say something” — something, that is, beyond itself. “A poem (…) is something”, then, that already includes both a composing act and a composed something and understanding the poem means understanding the relation, internal to it, between these. Exactly this is — “its principle”.

McLuhan formulated the point as follows (in what amounts to a close rephrasing of the Baudelaire/Eliot passage):

the symbolist poet makes of the poem not a vehicle for views, ideas, feelings, but a situation which involves the reader directly in the poetic process.⁷ That is why he [the symbolist poet] will always say that the poem is not about anything; it is something. It doesn’t say anything, it does something. (Catholic Humanism and Modern Letters, 1954)

Such understanding was not something that poetry could simply ‘say’.  Instead it was something that poetry could only attempt to activate by motivating the repetition of what had already taken place in its composition.  As McLuhan observed in paradoxical fashion:

We have to repeat what we were about to say. ⁸

At Cambridge McLuhan had encountered the work of Eliot along with that of Pound, Joyce and Lewis. Now he was working his way through all these figures once again with Kenner, reflecting not only the stimulus of Kenner’s exceptional mind, but also the combined influence of his meeting with Pound in June 1948, his exposure to the cybernetics of Wiener and Deutsch via Sigfried Giedion and his renewed appreciation (seeded already at the University of Manitoba) for communications via Havelock, Innis and Richards. The key point he began to find everywhere (not least in modern management theory introduced to him already in St Louis by Bernard Muller-Thym) was the central importance of the subjective act of perception qua composition. As Eliot translated Baudelaire: “the goal of poetry is of the same nature as its principle” — its “principle” being what has brought it into being, what has eventuated in the fact that “it is something”.

To take a concrete example, Pound’s Cantos manifestly⁹ requires the participatory work of their readers in order to be understood. But this achieved understanding is exactly of this work as informed by it. By working to understand Pound’s verses, his audience was to come to understand what it was doing as a species of what Pound also was doing in putting them together in the first (“principle”) place —  putting them together as a certain “something”. Readers would “retrace” the labyrinth of the work of composition in order to understand the poetry via what Pound had done in creating it.  As McLuhan would insist for the rest of his life, creation (eg, what Pound had done) and perception (eg, of what he had done) could be understood only together. Communication took place, he saw, only when these unite in some mysterious, magical, way. As he repeatedly cited Blake (although usually negatively): “They became what they beheld”. ¹⁰

So the learning of language by a child, for instance, at once socializes the child’s perception by restricting it to a set of particular parameters (this language, this dialect, this place, this time, this family, etc) and initiates it into a transformed and greatly enlarged world.  Similarly with, say, a telegram.  A telegraphic message is subject to a very particular set of parameters  — but the message is delivered and just this is the great mystery.

The great mystery of communication is that what closes — the bound circle of understanding, “they became what they beheld” taken negatively  — is also what opens — “they became what they beheld” taken positively.

Eliot notes this effect in his 1948 lecture:

Poe had, to an exceptional degree, the feeling for the incantatory element in poetry, of that which may, in the most nearly literal sense, be called ‘the magic of verse’. (…) It has the effect of an incantation which (…) stirs the feelings at a deep and almost primitive level.

As very frequently noted by McLuhan, Eliot had described this “magic” as the work of the “auditory imagination” in his Norton lectures at Harvard in 1932-1933:

What I call this “auditory imagination” is the feeling for syllable and rhythm, penetrating far below the conscious levels of thought and feeling, invigorating every word; sinking to the most primitive and forgotten, returning to the origin and bringing something back, seeking the beginning and the end. It works through meanings, certainly, or not without meanings in the ordinary sense, and fuses the old and obliterated and the trite, the current, and the new and surprising, the most ancient and the most civilized mentality. (The Use of Poetry and The Use of Criticism, 111)¹¹

But how does this actually work?  How is this actually done when something is created and when that something is understood by others?

This is the Road to Xanadu, described by Lowes (1927) and Havelock (1946-1947) and then taken up by McLuhan around 1950 when he underwent his second conversion.