Thomas Sutcliffe: The poisonous fantasy of these fairytale marriages

They're already rounding up the usual suspects. A celebrity relationship has collapsed and inquiries are under way as to the causes of the tragedy. "Career pressures'' is in the frame, as usual, and it won't be very long, presumably, before someone mentions the goldfish bowl of fame or the curse of Hello. But the culprit is much closer to hand, and its fingerprints can be seen all over the accounts of the break-up of Kate Winslet's marriage. She hasn't fallen prey to glossy photo-spreads but to the blight of the happiness myth.

The first thing to say about this sundering is that only the profoundly credulous would be startled by it. "The shock separation was said to be the culmination of weeks of arguments between the couple'' one tabloid reporter wrote. Clearly not that much of a shock then, except, that is, to those who have been protected from such details by a press determined to present this union as a kind of Platonic ideal.

"Their marriage was always seen as one of the most solid in showbusiness'', another paper observed – effortlessly skating over the fact that they had been married a mere three years. And who had "always seen'' this marriage as a model of granite durability? Well, the tabloids themselves, of course, who never missed an opportunity to gloss Winslet's domestic circumstances as perfect.

To be fair, there are some signs that she resisted this infantile simplification of her life. "Having a baby has strengthened the relationship'', she confided to In Style magazine, "although there are highs and lows and, at times, it's tough''. But she also fed the myth, in interview after interview. "When you know, you know – that's what I've been told all my life – and now I know'', she said about her first encounter with husband-to-be Jim Threapleton.

Later, interviewed about her role as Iris Murdoch in a forthcoming film based on John Bayley's memoir, she said, "the film gives me inspiration to see how Iris and John worshipped each other. They seemed to have their own magical, untouchable world. That's what I want and intend to have with Jim''.

You might think that anyone who sets out to build their marriage into a "magical, untouchable world'' deserves to come down to earth with a bump. But Winslet is only guilty here of succumbing to the fantasy that she helps to promulgate.

Indeed there's a curious ambivalence to the clichés of celebrity bliss that precisely echoes the swoony delusion of that remark. The journalists talk of "fairytale weddings'' and "dream homes'' and "fabulous lifestyle'', acknowledging that this is all a chimera at the same moment that they lay it before us as achieved and enviable fact.

And it's in the envy that the poison of the happiness myth lies – a poison that can turn back even on the notional possessors of this perfection. The idea of "the blissfully happy marriage'' is damaging enough for most of us but what must it do to those regularly depicted as paragons of matrimonial happiness? How deeply must the acid of invidious comparison bite into them? In truth, to ask of someone whether they are happily married is as meaningless as asking a person whether they have nice weather where they live – it mistakes a dynamic state for a static one. It also implies that happiness comes as a banded pack with a husband and wife – rather than being a hard won by-product of matrimony.

The framers of the Declaration of Independence got it right. We have a right to pursue happiness, but we would all be more content if we had modest expectations about catching it. Next time round. Kate Winslet should talk a bit less about possessing happiness and a bit more about working towards it. I can't say what it would do for her but it would be a small contribution to human happiness in general.

t.sutcliffe@independent.co.uk