OK yah, the rise of the Eco Sloanes

The book's production qualities are ropey in a way one had quite forgotten. But the content, presented as though to help a Martian make himself the perfect Sloane, is extraordinarily detailed, observant and imaginative. It still merits its cult reputation.

Cooler, Faster, More Expensive: The Return of the Sloane Ranger by Peter York, with, this time, Olivia Stewart-Liberty (Atlantic Books, £19.99) is completely feeble, by comparison - lazily put together, no more than a distended magazine feature, with very little specific taxonomy.

The authors offer their excuses. The world of the Sloane is just much less cohesive than it was, for two main reasons, they say. City deregulation in 1986 suddenly meant that the old-boy network no longer worked, a process completed by the Lloyd's crash. Meanwhile, Diana Princess of Wales, at first sight an archetypal Sloane, became a monster and changed the Sloane template, bringing in celebrity, fashion and alternative nuttiness.

So if they can't pin down Sloane characteristics quite so clearly any more, it's not their fault, they hint. There are all sorts of Sloanes now, supposedly, Sleek Sloanes, Party Sloanes, Euro Sloanes, Thumping Sloanes, Chav Sloanes, Bongo Sloanes even - these being the ones who like alternative therapies.

The most interesting identification they make they have, understandably, put first: Eco Sloanes. Here they usefully make explicit something that's always been obvious - that being green has become a significant social distinction.

There's Zac Goldsmith, the prince of eco - "more handsome than the sun, richer than Croesus, married to an exquisite model, with a townhouse in Chelsea and an organic farm in Dorset", the authors gush. These are the people we hear from most on green matters.

It all works a treat for the Sloanes, too. "Green is the stick with which the Eco Sloane can beat the vulgar rich." Sloanes may have lost their comfortable financial dominance and been shunted out of SW1 and SW3 and the better country houses, but they can still wield green distinction. And all of it - Hugh Fearnley-Whittingstall, Otis Ferry, farmers' markets, Daylesford Organic, Duchy Originals - suits their purposes perfectly. "Green is about conservation which suggests having something to conserve," you see.

That's one big reason why the toffiest Tory Party for ages will parade itself at its conference this weekend as the greenest ever. Almost worth the price of the book to get that clear.