This is an extraordinary discussion which is ostensibly about the theatre, but which quickly turns to technology - first of all the technology of the set designer, and then to the distinction between actors and audience, consciousness and the subconscious. At a more superficial level, it's an argument between old men about whether to turn the TV off!
Auden appears rather reactionary and childish compared to McLuhan's cool and detached analysis ("There is no audience any more... everyone's an actor"). McLuhan accuses Auden of 'acting' the part of the Oxbridge englishman.
Of course, now we can look back at the legacy of these people. Much of Auden's work remains powerful and will no doubt be read for centuries to come. McLuhan has largely been sidelined to the history of thought about technology (much to our loss), and Buckminster Fuller remains a hero for a small group of scientists.
Are they listening to each other? Something is happening here as they probe each others constraints. At the root of it, I think, is that McLuhan is a political radical dressed up as a conservative analyst of technology and society, and Auden is a political conservative dressed up as a radical. McLuhan has a lovely put-down to Auden, who says he does not own a TV: "You merely suffer the consequences of TV without enjoying it!"
McLuhan points out that a thread in Auden's work is the elision of the public and private realm: McLuhan postulates that what has occurred is a kind of Freudian pushing of the subconscious mind into consciousness (Auden seems suspicious of this representation - but he senses where the argument will lead). Hannah Arendt made a similar point in the Human Condition. Today, when we consider Big Brother (the show), big data, internet porn and social media this does seem an acute observation - although of course now we know that the market is a big player in the process. The Freudian distinctions aren't good enough any more.
Auden's foppish objections to McLuhan are really a reaction what he may feel (but does not describe) as an ontological flattening which lies behind McLuhan's arguments. At the heart of it is the assumption of 'functional equivalence' between different media and a failure to make deep distinctions between reading, thinking, watching and acting.
SO what would they say about Facebook and Google?