I love it when people talk dirty to me - so long as they know how to do it properly

Attended a reading of a play by the novelist Philip Kerr in a creaking upstairs room at the Old Vic last week, enjoying it no end. We do not often speak of enjoyment in this column, being of the opinion that there is altogether too much of it about, but credit where credit's due. Not least of the satisfactions of a reading is that it spares you having to sit through a production, with curtains, costumes, scenery, coughing – distractions, all, from the business of imagination. Two minutes into it and you've stopped noticing that the actors are turning the pages of a typescript and sit down only when they've finished standing up.

Soon, language takes over from performance, and you become a thing of ears, resonating privately, however public the arena. The rare pleasure of this, allowing that most solicitations on our attention these days are visual, explains why people are forsaking television for radio. The world is a less stupid place when we only listen to it.

It is also more naked. Which might be why I found myself intermittently embarrassed by the swearing in Philip Kerr's play, though it, for its part, was dramatically appropriate, and I, for mine, am normally a friend of obscenity. In exact proportion to the intensity of one's concentration did those now familiar four-pronged words of the sexual battlefield gain ground on their old shockingness, not because of who one was with or near, but because of how they sounded and what they meant in themselves. Good for the play, in that case. Re-energising the language is part of what plays are for.

But there was something else. Could the real reason for my awkwardness have been that Philip Kerr's characters did not swear as I swear. Infinite are the subtleties of the F word, and their subtleties were not my subtleties. A proprietorial thing. I like to hear people say "fuck" the way I say "fuck".

And that must work the other way round as well. I recall Time Out sending a young comedian to my house, four or five years ago, to interview me about Seriously Funny, a book and television series on comedy I'd just finished. Stories of betrayals by interviewers posing as admirers are legion in my business. You invite them into your home, serve them tea, let them spill white powder on your carpet, find them batteries for their tape recorders, invite them to make free with your lavatory, give them career advice, end up all but adopting the little bastards, and then, when it comes to writing up their articles, they treat you like shit.

In fact this particular little bastard made a fair job, for his age, of understanding and remembering what I'd said, but he did do one unforgivable thing – he accused me of peppering my conversation with swearwords in order to curry favour with him.

The arrogance of it! To suppose that I would bend language, the tools of my trade, in order to do what – appear cool? – in the eyes of a tit who as yet barely had language of his own. Stephen Lea, I think his name was. Though I wouldn't be surprised to learn he changed it after that. I haven't heard of him since, anyway. Maybe he went into a monastery. But I shouldn't be too hard on him. He was merely being squeamish, starting from obscenities that did not ring true to him because they were not delivered as he delivered them. It's also possible he saw me as such a strait-laced person that he could not believe I swore naturally in my own home.

And he has something there. I am myself surprised by how I have taken to swearing after so unpromising a start. I doubt I swore at all until I was 15. There was none of it at home. Even out of the house, in the rough and tumble of the markets where we ran a stall selling mouldy chocolates and chalk wall-plaques, the moment anyone began a word beginning with a consonant from the first half of the alphabet my father clapped his hands over my ears. Whether he swore in other company I never found out. But my mother goes on faithfully disapproving of indecency, especially mine. "I don't think there's any need for it" is how she puts it.

"Reason not the need," I tell her. "Reason luxury. Filth just makes some of us feel boundlessly alive, ma. Read Seriously Funny." That usually stops the conversation.

Of course, it's equally true that on another day foulness doesn't make you feel alive at all. Get it wrong and swearing is the most depressing act on earth. "The language of our whole nation," Ford Maddox Ford wrote in 1922, "is of an aching filthiness that would add to the agonies of the damned in hell."

Go on to many a council estate in 2002, and you won't find much changed. Kids of four or five badmouthing one another as though they were conceived in hell and have spent their brief lives living somewhere even worse.

Don't permit the lower orders to swear, I say. At least not until they've been trained in the music of it. To measure shock, to return zest to language that has been bled dry of life, to register another individual's sense of delicacy sufficiently to lay effective siege to it, requires artistry of the most refined sort. That, presumably, is what the fulminators in our popular papers have been trying to tell Ali G all week – that a foul mouth is no less subject to the laws governing aesthetics than a melodious one.