TOGA? Sexy. Prayer gown? Not sexy. Coat of mail? Sexy. Coat of many colours? Not sexy. Armani suit? Sexy. Birthday suit? Not sexy.

Anyone who has ever looked at a copy of Playgirl knows that there can be something less alluring about a naked man than about a man whose contours are draped in twills and tweeds. If Anne Hollander, the American art historian, is right, this has been true for at least 200 years, ever since the highwayman came riding decked out in a French cocked-hat, a claret velvet coat and doe-skin breeches. The highwayman was wearing one of the first suits; a rather poncey suit, perhaps, but a suit nonetheless.

Most of us, if we have thought about it at all, have probably considered the man's suit to be a drab camouflage: it can expand to contain the Churchillian midriff, drape to widen the angular frame, or endlessly duplicate itself to clothe legions of City employees. To Hollander, however, the suit is a sort of male 'fake traditional dress', or 'pseudo-ethnic costume. . . that commands general respect and avoids unfettered personal fantasy'. In Sex and Suits, a paean to male finery just published by Knopf in the US, she breathlessly charts the slow build-up toward the suit; from the androgynous sashed tunics of the Dark Ages, through full body armour (when, she says, men first found they liked being measured and having their forms puffed up) to its present genteel incarnation.

To Hollander, the modern male suit is much, much more than genteel: it is the embodiment of the nude male classical ideal from Discobulus to the David. When Hollander sees a man in a suit, she sees a sexual projection. 'The suit,' she writes, 'is a nude suggestion'.

This idea caused my friend Alexandra to collapse in hysterics. 'To me, a man in a suit looks like a package,' she said. 'It makes me want to giggle. They look like they've been wrapped up in paper and tied with matching ribbon. It's handsome but it's silly, and it certainly doesn't heighten what's in the box.'

Other women think a man in suit still packs a wallop. 'Suits are really sexy,' gushed a striking 26-year-old. 'If I see two handsome men, one in a suit, one in jeans, I'm going to go for the suit, every time. But then, I always date older men.' Her friend agreed: 'I'd rather be approached by a man in a suit than a man in jeans. I'd be more curious about the man in the suit, though I'd be intimidated. The man in jeans would seem more accessible - but I guess ultimately accessible is not a turn-on.'

Men admit sheepishly that they buy Hollander's point. 'When I'm in a suit I feel a little more courtly, more powerful,' said Ted, a 27-year-old mountain climber who rarely wears anything but sandals, jeans and T-shirts. Jay, who now works in publishing but used to sell clothes for Ralph Lauren, maintained that 'a handsome man in a great suit is like a picture in a beautiful frame. I like to wear suits, I'm the kind of guy that likes costumes'. 'Suits emphasise your shoulders, jeans emphasise your hips,' volunteered Hendrik. 'Suits are power, jeans are sex. That's why I wear them on alternate days.'

The professional view is more straightforward. Fashion consultant Anne Maxfield does not think men's suits breathe mystery. 'There's only so many things you can do with a shirt, a coat and a tie,' she said. Though no man, she conceded, looks bad in a dinner jacket.

(Photograph omitted)