What a seductive price £19.99 is. If this book were £20, I wouldn't advise anyone to buy it (although it is a very fine book indeed); yet at £19.99 it represents a fantastic bargain, being in every respect a lavish volume, hardback, full of beautiful full-colour illustrations, secured for under 20 quid. It should be possible to divine the point between £20 and £19.99 where the purchase of Dr Clock's Handbook becomes not simply attractive, but somehow an ineluctable consumer choice. For, as with the marginal preference theory in classical microeconomics, there must be a quantifiable amount at which the book becomes preferable to other non-essential purchases we might entertain. (In my own case, melon-flavoured condoms and a small plaster bust of the late Albanian dictator Enver Hoxha spring to mind.)

£19.995 would seem the obvious tipping point; and yet, when I come to examine my own feelings, it transpires that this is not so. Nor do I find £19.994, £19.993 or even £19.992 to be the price at which Dr Clock's is the book for me. Fortunately, using the valuatascope pioneered by the Nobel laureate economist Milton Friedman, I am able to peer deep within the subatomic structure of money itself. Here, even though the values observed are so infinitesimal as to be of no real application in the world of human commerce, I am able to discern the tipping point - £19.99178555 - where the absurdity of buying Dr Clock's becomes altogether justifiable. If the chains slap a discount on this one, I'll be carting copies home by the skip-load.

But then, I am an absurdist myself, so I'm bound to think this way. For me, the absurd is a debatable land where I happen to own a second home. It marches on one border with satire, on another with whimsy, on a third with slapstick, on a fourth with surrealism (indeed, entire swathes of the absurd are really only surrealism with gags), and on a fifth with the absolutely unmediated unconscious, where the disturbing chimeras of misfortune and bad mental health copulate and recombine. The absurd inverts expectations and perceptions with equal delight. It is equally present in the trompe 'oeil of philosophy, the pratfalls of politics and the echolalia of literature. The absurd is a nerve, not a posture; it can only be struck, rather than defined.

And so, our response to the absurd is deeply personal - one person's absurdity is the next's brutal reality, the third's piddling puerility. The absurd has an indeterminate valency: combine it with one psyche and nothing happens, with another and there's the most astonishing effervescence. So it's no surprise to me that I take issue with both definitions of the absurd put forward in Dr Clock's - how could it be otherwise? Mel Gooding, coming from an art-critical perspective, offers up the absurd as a kind of pabulum for our metaphysical queasiness, a way to untangle empirical conundrums: "the world may not be either as we see it or as we know it". For him, to "absurdify" life is to embark on a series of existential leaps across the courtyard of our Lord Time's bouncy castle. He cites Heisenberg and Einstein, and gives us Dr Clock's as "a practical corrective to solemn over-certainty, about the time or anything else".

By contrast, Andrey Kurkov, the Russo-Ukrainian writer (who is no stranger to the absurdity of this designation, or many others), provides a definition of the absurd that is grounded in a chilly political reality. Kurkov's absurdist mentor is Daniil Kharms, whose deceptively facile little tales were in fact deeply subversive of the totalitarian Soviet Union, with its savagely enforced monopoly - as Kurkov would see it - on all forms of absurdity. Thus, for Kurkov, "all absurdity arises out of an over-abundance of order". And: "Furthermore, attempts to classify the various forms and types of absurdity into a science only increase the density of absurdity in our lives, which pleases me no end."

So far, so Keith Chegwin. Yet there's something Marxian going on, even in Kurkov's impassioned rejection of a "science" of the absurd. He seems to be proposing the absurd as a praxis: the practical interaction between humans and their material reality that leads to a new - and equally absurd - synthesis. But this dialectical absurdism does not, he says, have to be pursued. Nodding to Nabokov, who, in a lecture entitled "The Art of Literature and Common Sense" defined the absurd as the creative actualisation of the irrational, Kurkov comforts us by saying: "We no longer need fear 'the infection of common sense' or the expansion of the absurd because it now blends harmoniously with our lives." Is Kurkov saying that it's unimportant whether the absurd is in the hands of the rulers or the ruled? Or is he calling upon us to take up absurd arms and fight it out with the Society of the Absurd Spectacle in a reductio ad absurdum of a battle?

I don't think he really knows himself. As I mapped out above, the absurd marches only part of its border with satire: it is one of the weapons in the satirist's armoury (in Russia alone it has proved terribly effective; behind Kurkov and Kharms stand Bulgakov and Gogol), not the casus bellum itself. By subsuming the absurd to the satiric Kurkov unwittingly propounds such paradoxes. Gooding is quite as unconvincing. His absurdism-as-therapy recalls the later Wittgenstein's aims of "healing" us of our inclination towards posing upsetting, metaphysical questions to ourselves: "Why am I here?" "Why are you there?" "Why is the draught excluder in your mouth?" But in place of portentous (and verging on the absurd) investigations of common language usage, Gooding would have us titter in the face of the infinite.

No, I think Nabokov is closer to the core of the absurd when he stops with the merely irrational. And yet the absurd isn't simply irrational - it's a particular kind of irrationality, or rather, I would argue, the representation of a particular kind of irrationality: the incomplete absorption and ineffective deployment of orthodox systems of ordering; a "crazy logic" that is itself internally discontinuous. This comes close again to what Gooding proposes, and yet his view of the absurd is too fraught with considered and adult intentions. For we all know who the absurd's greatest and most creative practitioners are: children.

Some examples culled from my own experimental subjects: "What if you had eyes in your feet? Would you see your socks?" "I'm going to make a million pounds by writing a book called How to Make a Million Pounds. On every page it will say the same: 'Write a book called How to Make a Million Pounds." And - my personal favourite this, uttered in 1997 by my then seven-year-old son in response to Diana Spencer's death - "She had to die, because her name was Di." I could go on - and so, no doubt, could you. Collecting the absurdisms of our children - or rather, revelling in them - is perhaps the greatest antidote to the high seriousness of the procreative undertaking. The collective psyche's way of balancing the books.

Naturally, just as there's nothing less surreal than a dream recounted, so the retailing of absurdist anecdotes propels them insistently through normalcy and towards banality: "Ooh! He says the funniest things!" Herewith lies the problem with Dr Clock's - and, indeed, anything that offers itself as a digest of the absurd: the very ascription invites its negation. By denoting something as "absurd", we cannot avoid questioning it and, in so doing, becoming aware of our status as perceivers. Children's absurdity takes place fully in the world. It makes no apology for itself, it simply is. All children are Gregor Samsa, awakening to discover they have metamorphosed into giant cockroaches during the night, and then simply having to get on with it.

The purest of adult absurdism goes with the Kafka principle: it is entirely framed by itself. Borges's "Tlön, Uqbar, Orbis Tertius", like many other of his fables, invites the reader into a world that is constructed solely out of a discontinuous and wilfully unassimilated logic, that just happens to be coextensive with our own. The same could be said of the Bonzo Dog Doo-Dah Band's "The Intro and the Outro", from the album Gorilla. After 20-odd minutes of specious musical doodlings and deadpan quips, the line "Adolf Hitler on vibes" is at once preposterous and appropriate. Closer to home - because Redstone Press is his publisher and does a fine job of it - David Shrigley's world, where botched orthography melds perfectly with duff doodles, is entered into through contemporary chapbooks with titles such as Kill Your Pets, which render them absurdly credible.

None of this is to say that Dr Clock's is not a fine place to start if you're in quest of the absurd. I must declare an interest here, because I've known Julian Rothenstein, the Redstone impresario, for 25 years now. Indeed, when he was the art editor at the New Statesman, he was the first person to publish my own absurdist cartoons. Over the past decade and a half, Rothenstein has built up a unique kind of publishing, first with his "box books", then with the Redstone Diary and other excursions: Mexican woodcuts, Chinese beau coupage. Redstone books are always beautifully produced, compulsively collectable, and oddly timeless. All of these values are present in Dr Clock's.

Here, too, are the prose of Fernando Pessoa, J G Ballard and Bertolt Brecht; the artefacts of Cornelia Parker, Damien Hirst and Marcel Duchamp; the graphics of Ed Ruscha, Pavel Büchler and Robert Filliou, as well as a host of other treats. Dr Clock's demands close scrutiny, but despite its asserted aim of being a "definitive guide", don't linger. Look and read in dinosaur-shaped turkey nuggets of time, because if you look for too long - as I did - you become insistently aware that the knitting-pattern photographs, line drawings from golf manuals and other curious ephemera that pad out its pages are absurdisms in our eyes only, while for those there at the time, they were instructive, practical, serious even.

I recently (within the past decade) saw a fine production of Beckett's Endgame starring Michael Gambon and the comedian Lee Evans. I don't for one second wish to downplay the Irish playwright's claims to be the pre-eminent stager of the Theatre of the Absurd, but on this particular night the most absurd thing in the auditorium was going on in the circle, where several coach-loads of provincial comedy fans had pitched up in the hope of a rib-tickling show. How my wife and I chortled as, within the first 20 minutes of Beckett's merciless evocation of the moribund mind, their laughter at Evans's elastic contortions gave way first to sullen silence, and eventually to audible depressed groans.

There you have it: the perceiver-dependence of the absurd in a nutshell. The recounting of the Endgame incident is more tragic than comic, but that, too, evokes the very performative character of the absurd, its need for enactment. As surveyed above, the territory of the absurd borders so many other demesnes that it's almost impossible, once you're on the move, to avoid seeking asylum in what the critic Julian Stallabrass has termed High Art Lite, together with Queen Tracey and King Damien, or in the Republic of Letters, with Jimmy Joyce and Artie Rimbaud. Staying stock-still in the absurd is impossible - like children, we are always growing out of it. Unless, that is, like the subjects of the most beautifully absurd image in Dr Clock's, you are lashed to a tree. This full-colour photograph is captioned: "North American real-estate salesmen celebrating the year's successes by undergoing a mock initiation ceremony." I'll leave the rest to your imagination - or your marginal preference.

Will Self's most recent and absurd novel, "The Book of Dave", is published by Viking