It's the way you tell 'em

SERIOUSLY FUNNY: From the Ridiculous to the Sublime by Howard Jacobson, Viking pounds

"Some men have to journey to the Congo to find truth stripped of its cloak of time. I'm more of a stay-at-home myself," writes Howard Jacobson, citing Conrad's Heart of Darkness as evidence of the deep, dark nature of comedy.

Stay-at-home? Oh yeah? On the very next page we hear about Jacobson's trip to Window Rock, the Navajo capital in Arizona, before an awe-inspiring itinerary unfurls - New York, Santa Fe, Munich, Pompeii, St Petersburg, Trinidad and many others besides - designed precisely for the purpose of stripping truth's benign, smiling features of their "cloak of time". And, for that matter, their pantomime-dame knickers and clown's greasepaint.

Part of the reason for such a wide sweep is that Jacobson's project is not merely a printed one. His assiduous digging up of funny bones and teasing out of ticklish propositions has been televised [a five-part Channel 4 series begins 4 February]. But Jacobson has his own breadth. He is thorough, persistent, cynical, and possessed of an intellectual generosity to match his subject. For his range is not just geographical; the analysis here is part anthropological, part historical, part literary-critical and part sociological.

And the end of all this rigour? Why, mortis, dear reader, the end of everything for we poor, bare, forked creatures. And if tragedy addresses the possibility that we can transcend this fleshly state, then comedy, Jacobson reminds us, ridicules such notions. So don't expect too many giggles from this book.

Yet, for all the comedian's pricking of our pretensions and debunking of our dignity, we do share the experience with him. We respond positively. We laugh. And this warm, liberating, cathartic way of asserting our humanity in the face of its very limitations is what fascinates Jacobson - the remarkable fact of what he terms our "exuberant persistence" (a phrase of which Samuel Beckett - a comic genius strangely neglected here - would approve). Despite everything, we can die laughing. Indeed, when one man did just that while watching "The Goodies" a few years ago, his wife wrote a letter of gratitude to the television programme's creators.

If it had happened in the United States, she probably would have sued them. And this aspect of things is also dealt with in this intensely argued book. Jacobson eloquently distances himself from those who would attempt to wallpaper over harsh reality, to pretend that humans can be politically, morally, physically or hygienically "corrected".

Not only does he poke fun at the happy-clappy American theorists of laughter, but he also speaks up for the likes of Bernard Manning and Roy "Chubby" Brown, whose work our current guardians of taste would seek to sanitise, or, worse, ban. Referring to widespread press indignation towards Manning for using the word "black" too often and offensively in a private performance for a group of off-duty policemen, mostly white, Jacobson offers a characteristic rejoinder:

"The argument that Manning was giving the policemen not just what they wanted but what they needed - lancing the boil, allowing the pus to run - was nowhere advanced."

Well, the argument is certainly advanced here, though I must say it doesn't altogether convince. I'm sure Jacobson is right about ethnic or racial humour "lancing the boil", and there is no doubt that jokes are as good a way as any to acknowledge the inevitability of prejudice and at the same time contain it. On the other hand, I cannot believe that such humour never sows the seeds of dangerous contempt, on the one hand, or dangerous resentment, on the other.

But what do you do about such material? Ban it and drive it into festering underground areas? Jacobson's answer is that, as a Jew, he feels "far more threatened by those who would wipe out ethnic jokes than by those who unthinkingly make them." My own is that you simply can't legislate and that, if a joke genuinely makes you laugh, its subject matter is not of any consequence; if it doesn't, it is.

I suppose, too, that the instigator of the joke ought, at the most fundamental level, to include himself - or herself, a la Jo Brand or Joan Rivers - as the object of the comedy. Which means, of course, that it is easier for a Jew to tell a Jewish joke, an Irishman an Irish joke, and so on.

Easier, but not essential. Say this one to yourself: A Catholic priest, an Anglican vicar and a rabbi are playing golf. Or at least waiting to play, for the people in front of them just can't seem to complete the first hole. Eventually, their patience snaps and they ask the club secretary to tell the other players to move on. "Certainly," says the secretary, "but can I just point out that those people are blind?"

"Oh dear," says the priest. "I feel such shame. I am properly humbled. Say nothing."

"I, too, feel ashamed," says the vicar. "What a tremendous example to others. Let them have as long as they need."

"Blind?" says the rabbi, "So can't they play at night?"

Well, is that offensive? And if so, to whom? It is, as Frank Carson says, relentlessly, the way you tell 'em. It all depends on how superior, if at all, the teller is trying to be. And, if you stop to think about it, you have only to look at a performer like Bernard Manning to be able to say: "Well, you've got nothing to feel superior about, chum."

In fact, the very notion of superiority is, according to Jacobson, what comedy is concerned to explode. As with tragedy, this is nemesis but, instead of pitiful emotion and moral grandeur, it excites the scatological, the primitive, the anarchic. Unchecked, therefore, it would surely be dangerous, but it seems that it has built-in checks. Laughter is restorative, a ritual unleashing of basic appetites, a "communal purgation" - this last is enjoyed, on one occasion, by Jacobson with a Blackpool Pier crowd watching Roy "Chubby" Brown.

Then, suitably purged and restored, we can return more effectively to the curbs, compromises, codes and caring that sustain society. Different societies have different comedic rituals for the necessary release from these constraints and Howard Jacobson has had a high old time reading up and witnessing a few of them, making the appropriate comparisons and connections. Thus, there is much baring of normally "private parts" and slopping around with urine and faeces. Or their symbolised equivalents - Jacobson is present at another act of communal purgation at the seaside, this time a pantomime in Bournemouth where two performers pour quantities of brown slime into each other's trousers, squeezing it until "it squelched out at last through the bottoms of their trousers, a shaming slushy sticky custard the colour of shit".

From ancient Egypt to modern America, it seems, virtually all societies have had this humorous safety valve, the operation of which they have entrusted to licensed clowns. Some of the most colourful and extreme rituals have historically been found - and chronicled in detail - among the pueblo Indians of North America: the Hopi and the Zuni. And it is "precisely because" such societies are "particular in matters of hygiene and hospitality that they look to clowns to be otherwise".

If all this chaos theory sounds lowering and without hope, it isn't. "Defecation," writes Jacobson, "is the mother of hope." We will always "spill over". And his embrace is not only wide, but warm and celebratory. We may be in the mire, but we're all in it together. Coarseness, insult and invective can, when well-tuned, have us all slapping one another's backs in unity.

`Seriously Funny' begins on Channel 4 on 4 February