As rhetorician, Mr. Empson has brilliantly availed himself of the new insights of Freud and Jung into traditional speaker-audience relations. The Seven Types of Ambiguity is an ingenious and valid application of Freud’s analysis of wit and of dreams to some of the material of poetry. Insofar as political and social myth-making is inevitably part of the material of poetry, as it is of language, it too can be subjected to psychoanalytic scrutiny with fascinating results. (Poetic and Rhetorical Exegesis, 1944)

Increasingly, I feel that Catholics must master C.G. Jung. The little self-conscious — unearned — area in which we live to-day has nothing to do with the problems of our faith. Modern anthropology and psychology are more important for the Church than St. Thomas today. (McLuhan to Ong and McNaspy, December 23, 1944)¹

La trahison des clercs has been to subordinate detached critical intelligence to the servile functions of ‘political’ evangelism. They are thus the inheritors of the sectarian enthusiasms of the sixteenth and seventeenth centuries presenting a scientific demonstration of Jung’s social principle: “No psychic value can disappear without being replaced by another of equivalent intensity.”² (Footprints in the Sands of Crime, 1946)

As Father Victor White wrote concerning ‘Jung and the Supernatural’³: “A living symbol does something to us; it moves us, shifts our center of awareness, changes our values. Whether it is just looked at, or heard, acted out, painted out, written out, or danced out, it arouses not only thought, but delight, fear, awe, horror, perhaps a deeper insight.” That is, (…) symbols are not just referential signs. They don’t just say something. They do something. And saying is also symbolic action. We are moving very rapidly today to a grasp of scriptural, poetic and social communication which promises to take up all the wealth of patristic insight and to go far beyond it. But we have no choice. We have either to surpass any previous age or to collapse into a new Babel. For our problems, like our means and opportunities, are of a scope beyond those of any previous age. (Symbolist Communication, 1953)⁴

McLuhan read Jung in the early 1940s, if not already in the 1930s,⁵ and at the time valued his work very highly indeed (as evidenced in his 1944 letter to Ong and McNaspy above). But the eventual influence of Jung on McLuhan’s work may have been more unconscious than conscious and taken decades to unfold. It was above all in that perpetually indistinct area of what Jung termed the “energetics“⁶ of consciousness⁷ — aka, the “enantiodrama“⁸ of consciousness — where that influence, appropriately enough, would eventually set to work. That is, McLuhan, having ‘put on’ role after role after role in three decades of tireless talking and writing, finally found one that could be ‘set to work’ to focus communication problems — and this in that very figure/ground “enantiodrama” that had previously stumped him.⁹

Jung himself set out his take on “energetics” especially in Two Essays on Analytical Psychology:¹⁰

• Life is born only of the spark¹¹ of opposites.
• Heraclitus (…) discovered the most marvelous of all psychological laws: the regulative function of opposites. He called it enantiodromia, a running contrariwise, by which he meant that sooner or later everything runs into its opposite.
• There comes [at some point in an individual’s life]¹² the urgent need to appreciate the value of the opposite of our former ideals, to perceive the error in our former convictions, to recognize the untruth in our former truth, and to feel how much antagonism and even hatred lay in what, until now, had passed for love. Not a few of those who are drawn into the conflict of opposites jettison everything that had previously seemed to them good and worth striving for; they try to live in complete opposition to their former ego. Changes of profession, divorces, religious convulsions, apostasies of every description, are the symptoms of this swing over to the opposite. The snag about a radical conversion into one’s opposite is that one’s former life suffers repression and thus is produced just as unbalanced a state as existed before (…) Just as neurotic disorders once arose¹³ because the opposing fantasies were unconscious, so now a different set of disorders arise through the repression of the former ideals. It is of course a fundamental mistake to imagine that when we see the non-value in a value or the untruth in a truth, the value or the truth ceases to exist. It has only become relative.
• Everything human is relative, because everything rests on an inner polarity; for everything is a phenomenon of energy. Energy necessarily depends on a preexisting polarity, without which there could be no energy. There must always be high and low, hot and cold, etc, so that the equilibrating process — which is energy — can take place. Therefore the tendency to deny all previous values in favour of their opposites is just as much of an exaggeration as the earlier onesidedness. And in so far as it is a question of rejecting universally accepted and indubitable values, the result is a fatal loss. One who acts in this way [also] empties himself out with his values, as Nietzsche has already said.
• The tragic counter play between inside and outside (depicted in Job and Faust as the wager with God) represents, at bottom, the energetics of the life process, the polar tension that is necessary for self-regulation. However different to all intents and purposes these opposing forces may be, their fundamental meaning and [felt intent]¹⁴ in the life of the individual always fluctuate round this centre of balance. Just because they are inseparably related through opposition, they also unite in a mediatory meaning, which, willingly or unwillingly, is born out of the individual and is therefore divined by it [alone and only when] it has a strong feeling of what could be and what should be.¹⁵ To depart from this [mediatory] divination means error, aberration, illness. 
• From a consideration of the claims of the inner and outer worlds, or rather, from the conflict between them, the possible and the necessary follows. Unfortunately our Western mind, lacking all culture in this respect, has never yet devised a concept, nor even a name, for the union of opposites through the middle path, that most fundamental item of inward experience, which could respectably be compared with ¹⁶ the Chinese concept of Tao. It is at once the most individual fact and the most universal, [and represents] the most legitimate [possible] fulfilment of the meaning of the individual’s life.
• For the primitive anything strange is hostile and evil. This line of division serves a purpose, which is why the normal person feels under no obligation to make (…) projections conscious, although they are dangerously illusory (…) Because the [neurotic] individual has this same primitive psychology, every attempt to bring these age-old projections to consciousness is felt as irritating. Naturally one would like to have better relations with one’s fellows, but only on the condition that they live up to our expectations — in other words, that they become willing carriers of our projections. Yet if we make ourselves conscious of these projections, it may easily act as an impediment to our relations with others, for there is then no bridge of illusion across which love and hate can stream off so relievingly, and no way of disposing so simply and satisfactorily of all those alleged virtues [of ours] that, [in our manifest altruism], are intended [only] to edify and improve others.