At the beginning of his 1954 essay ‘New Media as Political Forms’ (Explorations 3), written six months or more before the Culture and Technology seminar stumbled on the notion of acoustic space,¹ McLuhan revealed how ready he was for such a discovery:

For the lineal procedure of individual awareness, Joyce, in his last work, substituted an everyday roundabout with intrusions from above and below.² For those locked in the metallic and rectilinear embrace of the printed page, Joyce appears as a surrealist magician or clown. But his optophone principle (…)³ provides the key for future literary and social education. The optophone is an instrument for turning images into sounds. Surrounded by a vast new imagery, technological man has yet to learn how to interpret this imagery verbally or socially. Until he learns its language it will continue to act on him like the new liquid meat tenderizers.⁴

In advance of  ‘acoustic space’, this was already to suggest that we are “surrounded by a vast new imagery” of sound. Here in embryo was (a) McLuhan’s turn from literary works to interior and exterior environments (b) as specified by their dominating sense within the range of the sensorium. The rest of his life would be spent attempting to investigate into, and communicate about, this insight.

Furthermore, the new surround or environment, specifically of sound (dual genitive!) was translated from a previous surround of visual images (dual genitive!). Visual images, too, had once created “a vast new imagery”, one that began with the alphabet — the translation of sounds into visual letters — but received its decisive impetus from Gutenberg — the translation of letters into print.  Now that “imagery” of print was to be displaced, turn and turn about, by a renewed surround of sound — just as the optophone apparatus translated visual images into auditory sounds.⁵

The “optophone principle” captures in a single phrase McLuhan’s reading of Joyce and the dynamic basis of his own life’s work. ‘Opto’ as eye/sight and ‘phone’ as sound/ear are correlated over a range of ratios between the two — a range whose one extreme is the overwhelming emphasis on the eye relative to the ear, while the other extreme is the overwhelming emphasis on the ear relative to the eye. In the middle of the range, the two are in relative harmony.

The great question concerns the middle — the middle of the range, on the one hand, and, on the other, the changing middle of the eye/ear ratios constituting the extensive range of their relative emphases and valorizations. Not surprisingly, it is only from the middle of the range, where eye/ear are equally valorized, that the changing middle between the two over their range may be observed and investigated. Absent such a situation in the mean,⁶ hence assuming a position on one of the two sides of the range of sensory ratios, the virtues of the other side can never be appreciated. Indeed, such an inability to appreciate (in all its senses) is exactly what it means to be on one of the sides of the range of ratios.

McLuhan called this dynamic middle or mean or medium — ‘tactility‘:

tactility is not so much the isolated sense of touch as it is the interplay of all the senses. (Humpty Dumpty, Automation and TV, 1962)⁷

Tactility may be imagined as a kind of elastic band, fixed at its middle (Pound’s “unwobbling pivot”) that can be stretched in one direction or the other. This dynamic band of tactility (dual genitive!) as the mean governs all the values the two sides of the band, the visual and the aural, can take — relative to one another. “The medium is the message”.

When the band is relaxed, its ends or poles are close together and have a kind of natural repose or poise. Stretched in one direction, the poles are pulled apart in an action that distorts that natural repose but cannot overwhelm it. So with the other direction, in a mirrored way. The relation of the two sides of the band is dynamic, is not constant, but the fact of some relation (dual genitive!) is a constant — or, rather, relationship itself is the constant. “The ‘meaning of meaning’ is relationship.” (Take Today, 3)

Among other terms McLuhan used for this dynamic middle are ‘the gap’, “the interval”, ‘no-man’s land’ and “membrane”.⁸ This elastic structure must therefore be further imagined as an invisible, inaudible and intangible power like magnetism/electricity/gravity in which poles are dynamically related to each other by attraction and repulsion, by contesting centrifugal and centripetal forces.  

Now the range of these ratios is principial, it is first in multiple senses, the most important of which is that it defines the possible elements, or elementary possibilities, of human experience. That is, human experience is built from these elementary possibilities similarly, but not identically, to the way in which physical materials are built from the range of elements in Mendeleev’s table. (It is highly important to note, however, that different sciences focus on different levels of combinations of elements. Thus organic chemistry, for example, of course deals with the chemical elements. But it does so as these are ‘already’ combined into complex compounds. Similarly with genetics and medicine and all the other physical sciences except for basic chemistry. Now in the humanities it has generally been assumed that explanation should or must be, so to say, atomic. But this is not necessarily the case and the history of failure in the area suggests that it is probably not the case. Indeed, why should experiential structures be any less complicated than those of, say, proteins?)

It may therefore be suggested that McLuhan’s life-goal was to specify in an exoteric manner (= via open ongoing investigation) what he found already described esoterically in Finnegans Wake: namely, the “octophone principle” as a dynamic generator — or medium — of environments. Of experiential life-worlds.

Humans somehow have, or are, this principle. Tis Optophone Which Ontophanes. The shining forth (phanes) of realities (onto) ‘takes place’ via the  “optophone principle“. This can be termed the principle of the energizing ’tis’ — the principle of the dynamic coming forth by day of the ‘it is’.

The heart of the matter was, and is, to ask after the axis of such transformations between realities — plural —  and of its operation. What is the working, or phenomenology, of the repressed gap of the opto( )phone⁹ principle (as a dual genitive)? McLuhan’s answer in 1958: The medium is the message.

All this fell into place for McLuhan in the late 1950s. But the first steps he took in this direction were made at the start of the decade. A decisive moment came with the uncovering of “acoustic space” as differentiated from “visual space” in the Culture and Technology seminar in late 1954. But earlier that year McLuhan had already guessed the riddle with his announcement from Joyce of the “opto( )phone principle” governing our surrounds.