Since Radio 4 is such a joy to hear, it was no less a joy to hear that a record number of listeners now enjoys hearing it. And perhaps the most enjoyable thing of all about the news that Radio 4’s weekly audience has just reached ten million-plus is that this surely has happened in no small part because of what the ten million find themselves minus: we listen to Radio 4 not only for what it can do, but for what it cannot do. If it could do it, we should very soon stop listening.

It cannot, for example, do subcelebrity castaway programmes. There is no risk at all of switching on Radio 4 and hearing a swampful of talentless nonentities staring at the ground and picking their feet: listeners would have no way of identifying the oaths, moans, simpers, complaints and flatulences of invisible hapless jerks struggling to make hats from mud, squeeze pimples, barbecue rodents, move bowels or get one another’s kit off. Even if one of them dropped dead, nobody would know which. Because, though all this manages to make rotten television, it fortunately makes impossible wireless. What makes great wireless is one supercelebrity castaway listening to Charlie Parker and the Bach Double Violin Concerto while he leafs through Cymbeline and the First Book of Kings. He is not expected to make a grab for Sue Lawley, or appear, sobbing, in the red-tops the next day explaining why his marriage/career/nasal septum is falling to bits.

Nor, thank God, can wireless do makeover programmes. Radio 4 would be hard put to find ten million listeners eager to chuck themselves into their fireside chairs after the long day’s work was done in order to tune into an anonymous voice explaining that he was standing in a large room painted beige which he was going to transform into two small rooms painted puce, giving out on to a fly-blown garden his hortimaniac colleague was about to convert into a half-acre of pine planks with a polythene pond in it boasting a solar-powered plastic Triton that vomited spotlit water. Even if he explained that she would be broadcasting without a bra. Nor is television’s increasingly nauseating vogue for cosmetic surgery accessible to Radio 4: there is scant entertainment percentage in listening to a hammer breaking an excessively Roman conk, or a wattled neck being pulled back behind the ears and riveted in place, or a bust being so enthusiastically lifted, siliconised and tautened that if the lucky recipient wishes henceforth to smile she will have to cross her legs to give herself some slack.

And where would The Weakest Link or Who Wants To Be A Millionaire? be without the Torquemada smirk of the one, the Tantalus tease of the other, and the pitiable squirming of dingbat victims faced with the heavy task of identifying the capital of France but unable to choose between Paris and Doncaster? Certainly not on radio: so, since it lies far beyond the capacity of radio to convey something so unimaginable, ten million Britons may turn on their sets in the absolute confidence that the action will not hypnotically rob them of umpteen hours of their precious lives.

As snooker does. A week or so ago, I sped down from my attic sweatshop to make myself a quick sandwich and — feeling I deserved a break but witlessly failing to clock the risk inherent in the looming pun — tapped the remote to find Mark Williams in the middle of his own. I watched that break rise to 87. And continued watching till the sun went down. Soon after the sun came up next day, we were both back. This carried on for a week. That week will not come again. If, instead, I had remained in the attic during it, I might have, who knows, learnt three more banjo chords, finished my novel (I am a quick reader), eased the windows I shut just before Christmas and which seem to have decided they like it that way, put in order the thousands of books that have been in the wrong place ever since they arrived here from Cricklewood three years ago, addressed myself to the tricky matter of the square root of minus one, or finally got around to writing to all the readers who have written in to ask whether I am the same Coren who used to appear here on Wednesdays or am I another one of my bloody children.

It wouldn’t have happened on Radio 4. It couldn’t do snooker. Something persuades me to doubt that John Virgo would transfix millions of listeners by describing in detail how Jimmy White’s cue ball, having potted the red, had inadvertently knocked the blue into the line of the black and then whizzed up to the baulk cushion again, tragically cannoning the green into the one remaining red with such force that it had flown off the table and disappeared into Stephen Hendry’s Lucozade.

Doesn’t work, does it? Thank the Lord.

Join the Debate on this article at comment@thetimes.co.uk