from Bob Dobbs :
THIS IS PERHAPS ONE OF THE MOST IMPORTANT KEYS TO McLUHAN’S INVENTION:

15-16 The simplest way to get at Joyce’s technique in language, as well as to see its relation to TV, is to consider the principle of the electronic tube. The paradox of the electronic tube is that it is the means of breaking the conductor in an electric circuit. The tube permits the electrons to escape from the wire that ordinarily conveys them. But the tube controls the conditions of escape. It liberates electrons from the wire but it provides a new context in which they can be repatterned. The cathode inside the tube is one end of the broken conductor and the anode is the other. The anode attracts and receives the billions of electrons that are “boiled” off the surface of the cathode. When a tube is connected into an alternating-current circuit, the anode is positive during half of each cycle. During the half cycle when the anode is negative, electrons cannot reach the anode. It is this characteristic of an electronic tube which enables it to act as a rectifier, changing alternating currents into direct current.

16 The grid is the controlling or “valve” electrode of the tube. It is located between the cathode and the anode in the path of the electrons. By voltage control the grid acts as trigger for the electronic flow. Grid bias blocking electronic flow is recentralized by signal voltage. Signal voltage is a trigger that releases full flow of current through the tube. But this flow stops when anode voltage becomes negative. Cycle then repeats. The load of current on this cycle is a motor.

16 When current is too weak for direct flow, it can, in a vacuum tube, be used as signal voltage on the grid of the tube. Then every variation in the shape of the wave will be faithfully reproduced in the output wave of the tube. Thus a tiny amount of energy can be exactly controlled or stepped up instantly to very high potentials.

16 Now metaphor has always had the character of the cathode-anode circuit, and the human ear has always been a grid, mesh, or, as Joyce calls it in FINNEGANS WAKE, Earwicker. But Joyce was the first artist to make these aspects of language and communication explicit. In so doing, he applied the principles of electronics to the whole history of culture. The entire cyclic body of FINNEGANS WAKE is suspended between a predicate and a subject. The cathode-anode aspect of metaphor and language Joyce first extended to syntax. He took the charge of meaning out of the wire of direct statement into the vacuum-tube of the self-contained poetic drama of his “all nights newsery reel.” (FW489 – Ed.)

16-17 Metaphor means a carrying across. All speech is metaphoric because any oral sound is a gesture towards externalizing an inner gesture of the mind. The auditory situation is a gesture towards externalizing an inner gesture of the mind. The auditory situation is a carrying across from a silent situation. Writing is metaphor for sound. It translates, or metamorphizes the audible into the visual. There is necessarily discontinuity in metaphor. There has to be a leap from one situation to another. If I say: “I’ll take a rain-check on that,” I am breaking the wire of direct reply: “Sorry, can’t make it,” and creating an independent circuit. A social situation is carried across to a sporting event which is discontinuous with, but proportioned to it. The new circuit sets up a drama which reshapes and controls the initial situation. The social situation of refusal is transformed by the sporting situation of disappointment and deferred pleasure. A great deal of energy plays back and forth between these two poles. With a minimum of signal voltage, “rain-check” creates the mood of informality and spontaneous regret. All metaphors can, of course, be reduced to the four-part ratio as here: “My feelings in refusing your invitation – are to my usual feelings in such formalities – as when weather refuses to permit me – to see a ball game.” Or, “my feelings about your social invitation are positive even when the feelings about the deferred game are negative.”

17 Joyce carried these four-fold intellectual proportions into every gesture and situation in the WAKE. That is why it is always radiant with intelligibility when seen or apprehended. Here Comes Everybody is his cathode, Anna Livia Plurabelle his anode, and Earwicker or Persse O’Reilly his grid or triggerman. We are the main circuit into which this electronic tube is connected. We can thus see that the functions of a work of art, or electronic tube in the social circuit, are manifold. Principally, however, the tube provides a means of control which can step up the feeble signal voltage to greater intensities of manifestation. The tube permits multiple re-shaping of the ordinary current of small talk and gossip for many kinds of work. It is no exaggeration to say that all things in this “funanimal” (FW244 – Ed.) world were current for the tube of the WAKE. All the social currents that ever were, Joyce can easily adopt in the vacuum tube, or head, or glass house of the sleeping giant Finnegan. “This is modeln times.” (FW289 – Ed.) The plasticity of human experience can now be modelled in any shape desired. The nature of electricity applied to existing information about past and present tends by virtue of its instantaneous character to abolish the past and to waken the sleeping giant Finnegan who is the collective experience of mankind. Joyce saw that communication in modern times had altered our relations to the past and to ourselves. At the Renaissance the mechanical aids to knowledge had created an image of inter-stellar space which swallowed man. Today, a new technology of great delicacy and precision has created an image of ourselves which invites us to swallow nature. The gap between man and the world, art and nature, has been abolished. Toward the end of the WAKE, Here Comes Everybody says:

17 “Well, yeamen, I have bared my whole past, I flatter myself, on both sides (FW536 – Ed.)… and, as a matter of fact, I undertake to discontinue all practices (FW537 – Ed.)….”

17-18 The guilt of HCE or everyman has been probed from so many angles and has raised so many issues that the glass house of his memories is now an open secret. At this point the four old men who have been quizzing him yield to another group:

18 “We bright young chaps of the brand new brain-trust are briefed here and with maternal sanction (FW529 – Ed.) … All halt! Sponsor program and close down. That’s enough general, of finicking about Finnegan and fiddling with his gaddles (FW531 – Ed.)… His thoughts that would be words, his livings that have been deeds (FW531 – Ed)… and tell you people here who have had the phoney habit (it was remarketable) in his clairaudience (FW533 – Ed.)… to bring ruptures to our roars now I am amp amp amplify (FW533 – Ed.)…”

18 The young brain-trust, representative of 20th century science and broadcasting, brush aside the nightmare of the past, they summon the uttermost powers, and the whole newsery reel of the sons and daughters of Anna Livia Plurabelle fades into the new day. – Marshall McLuhan, “Radio and TV vs. the Abced-Minded,” EXPLORATIONS #5, June, 1955, pp.12-18