MOST men of a certain age must feel that they have watched, heard and read all they can take on the male midlife crisis. In fact, the pressure of media cliché may now be self-fulfilling. Frazzled, middle-aged blokes, of which I am a classic exemplar, may be tumbling into crisis because we are constantly told we are tumbling into crisis.

Nor is ours an exclusively middle-class affectation. Deidre, The Sun’s redoubtable agony aunt, regularly gives the subject of male midlife crisis its own dedicated helpline, so numerous are the demands for consolation or advice from her middle-aged male readers.

And the appearance in cinemas this weekend of Sideways is unlikely to improve our state of mind. It’s a bitter-sweet comedy about two fortysomething buddies who embark on a wine-soaked road trip in a desperate attempt to cling on to their evaporating dreams, or at least sow a last few wild oats before torpor mortis takes hold. In fact, the sight of audiences full of people who are young, good looking and (worst of all) female laughing themselves silly at this cruelly accurate depiction of middle-aged male angst in all its washed-up, shambolic absurdity is likely to be intensely irritating to chaps who feel themselves trapped in the doldrums of life.

Yet could we but rise above our fretful introspections, we might realise that our generation has a unique historic opportunity — for the very phrase “midlife crisis” has its 40th birthday this year. Bandied about to excuse every sin in the lumbering panoply of male indiscretion, it is now surely going through its own midlife crisis. So let’s subject it to the sort of questions it normally inflicts on us. What does it really mean? Is it an inevitable rite of passage — like birth, death, and dropping ketchup on your new tie? Is it triggered by tangible physical or social conditions, or just a trick of the mind? And, most important of all, need it be such a bloody ordeal?

For the man who coined the phrase, midlife crisis had a specific meaning. The Canadian social scientist Elliott Jaques was intrigued by the way that creative geniuses often experience periods of intense self doubt (frequently accompanied by self-inflicted domestic trauma), followed by a revitalised blossoming in a new direction. In his 1965 study he used the phrase to describe the pronounced ruptures we can observe in the lives of such diverse talents as Gauguin (who fled marriage, family and boring bank job to live in the South Seas, ogle naked natives and paint sublime canvases), Beethoven (who wrote the suicidal Heiligenstadt Testament, then reinvented the symphony), and Dickens (who abandoned his wife and ten kids, took an 18-year-old mistress, and proceeded to pen his deepest novels).

Even this limited use of the phrase, however, is problematic. In earlier centuries it was more usually syphilis, not crumbling self confidence, that forced bohemian types into a despairing midlife reappraisal of their options. And remember how much shorter life expectancy was in past eras. To us, Shakespeare’s decision to hang up his quill in his forties looks like a classic midlife crisis. But in Jacobean times, 45 was geriatric. The spectacle of 21st-century forty somethings whining “what am I going to do with my next 40 years?” would have struck even our comparatively recent ancestors — the young troops fighting in the world wars, for instance — as a nauseous display of pampered ingratitude.

But then, the very fact that there seem to be no “good brave causes left”, as Jimmy Porter complains in Look Back in Anger, itself contributes to the ennui of the modern middle-aged male. It was amazing to note, for instance, how many male newspaper columnists wrote gung-ho pieces after 9/11, welcoming the “big fight” for which “our generation” had apparently been waiting all our lives. There’s even a school of thought which maintains that the Iraq War is a manifestation of George Bush’s midlife crisis. Or that the Bush presidency is a manifestation of America’s.

When the phrase midlife crisis is stretched to encompass global politics, however, is it time to suggest that it has lost all semblance of meaning? I happen to think not. First, its very ubiquity tells us something about our times. This is an era full of Zeitgeists that seem specially summoned to blow apart the middle-aged male ego. One is our culture’s obsession with youth — a quality to be prized above all others, it seems, in the various rat races to which we are all conscripted. In such a babyface-fixated climate it is quite possible for a man to feel like a reject at 45.

Another of those Zeitgeists (and the reason, perhaps, why it is generally men who suffer midlife crises, when it is women who have to go through the physical trauma of the menopause) is the astonishing march of feminism.

When men were the undisputed masters of the public and private domain, as they were for 50 centuries before our own, they could ease themselves safely through their dangerous middle years by concentrating on the responsibilities and perks that their status conferred. Now this “birthright” has been revoked and reviled. Quite right too, you may say.

But the rise of the all-singing, all-dancing superwoman doesn’t lessen the sense of redundancy felt by middle-aged males.

So yes, given the world in which we live, it is inevitable that many men should experience crisis in their middle years. The big question is: can it be turned into a positive experience? Well, one man thought it could. The groovy writings of the psychoanalyst Carl Jung, so fashionable among hippies of the Swinging Sixties, may be disdained by today’s sophisticated shrinks. But for us bumbling amateurs, groping for a guide through the maze of life, his dissection of a classic midlife crisis seems as pertinent as ever.

Of course, he didn’t call it a midlife crisis, because he predated Jaques. But that only makes his analysis seem more universally applicable — to women as well as men, and to all generations rather than just the middle-aged.

Jung identified five psychologicial states (rather like the five acts of Shakespearean tragedy) through which an adult in crisis might pass. The first, probably instilled during childhood, is accommodation. For example, you may have the soul of a lion tamer, but your parents pressed you into becoming an accountant. So you accommodate. You repress your true preferences beneath a contrived persona that doesn’t fit you but nevertheless helps you to fit external circumstances. Quite possibly you don’t even know you are repressing anything, so powerful has been your conditioning.

But one day something snaps. This is Jung’s second stage: separation. You start questioning why you behave in ways that don’t make you happy. You realise that your adopted persona is a mask; that it can be separated from your true self.

Which leads to the third, most reckless, stage. Jung, no stranger to pretentiousness, called this “liminality”. A more down-to-earth word would be turmoil. It’s this phase that gives the male midlife crisis its terrible reputation. You have seen through the pretence of your old ways, but haven’t yet found any feasible alternative. Nevertheless, you throw off the mask. Cut loose. Drift aimlessly. Inflict mindless misdeeds on yourself and those who love you.

These misdeeds will traditionally include chasing women 20 years younger than yourself; re-engaging in laddish binges; impulsively quitting a steady job; and, of course, attempting ludicrously inadvisable physical challenges, such as rowing the Atlantic or (my own desperate fetish) embarking on 40-mile-a-day mountain hikes.

Sooner or later you will self destruct or emerge from this lamentable phase of infantile irresponsibility. The question then is whether you write it off as an aberration, offer profuse apologies to your spouse (if still married to you) and such friends as remain friends, and creep back into your boring old life — or whether you proceed intrepidly to Jung’s much more challenging fourth and fifth stages.

He called the fourth re-integration. By sinking so low, you have discovered things about yourself. Quite possibly they weren’t admirable things (not without reason did Jung call them the shadow self). But at least you now know about them. So you can start building a new persona that is more compatible with your true nature.

Which leads finally to . . . well, Jung’s equivalent of a state of grace. He called it individuation. By now you are aware that there will always be tensions between what you truly desire and what the world expects of you. Between selfishness and selflessness, in other words. But you have not only learnt how to balance these opposing psychological forces, you have also discovered that the very act of reconciling the seemingly irreconcilable is what gives human existence its depth and richness. And, ultimately, its worth and purpose.

In short, you have evolved — after decades of anguish — into that miraculous species that posh private schools claim to be able to nurture after a mere seven years of secondary education. Namely a rounded, balanced individual.

Alternatively, of course, as a self-respecting middle-aged chap with a mortgage to service, a wife to cherish, kids to raise, an employer to please and a golf club not to embarrass, you could avoid having a midlife crisis at all. It would certainly be simpler.

But wouldn’t life be intolerably duller without the spectacle of middle-aged men behaving atrociously? And where else could novelists and screenwriters find such a rich vein of tragi-comedy? And women such ready confirmation of their innate superiority?

No, there’s no doubt about it. After 40 years, the male midlife crisis is as embedded in Western culture as traffic jams and fast food. I just hope I can get through my hellraising “liminality” phase reasonably quickly. It can seriously damage your pension arrangements, I hear.