One of fashion's oddities is the hive mind, the way a single idea takes root in a season and infiltrates any number of collections (so everything seems to be coming up green or red or polka-dotted at the same time). Among the 20 designers from the Central Saint Martins M.A. fashion course who presented their graduate collections tonight, it was fascinating to see how many of them opted for penitential shrouds, long, layered tunic shapes (for men and women), and asymmetrical silhouettes that swept the floor, evoking monks and knights in equal degree. The clothes stood away from the body, often genderless, never reverting to fashion clichés like prettiness or seduction. "It's not shoulder to knee," exulted living-legend professor Louise Wilson, who is celebrating 20 years of guiding the M.A. course. "I'm fed up with a decorated dress."

But it would be too pat to say that, in their rejection of such a notion, the clothes celebrated individuality. They didn't. They were simply about a different kind of tribalism. The Occupy movement has refreshed a spirit of militancy in the popular debate, and there was a real edge of that here. It was easy to imagine the abrasive, passionate Wilson as a warrior queen leading her students on a crusade. There was even a crusade readily at hand. This is the last M.A. class to graduate from the old Saint Martins premises on Charing Cross Road, the seedbed that produced under Wilson's guidance the staggering list of alumni included in the show notes. The move to the new complex in King's Cross, where the college is now the linchpin of an urban regeneration project, has been a difficult, controversial one, with the ever outspoken Wilson ever speaking out. That's been her crusade, but like all such endeavors, it's a lost cause. Maybe that's why there was such an air of melancholy, even pessimism, in the clothes tonight. Yes, these people might have been crusaders at some point, but their battles were over and now they were hunkering down in survivalist communities, ingeniously crafting their clothes from the detritus of the civilization that had abandoned them.

There is some sweep to that generalization, because, obviously, there were exceptions. Like Erna Einarsdóttir's flecked sweater and gilded tweed skirt combinations or Hiroko Nakajima's color-blocked felts over knit leggings, which had something of Issey Miyake's esoteric athleticism about them. But the winners of the L'Oréal Professionnel Creative Award, whose collections conveniently topped and tailed the presentation, were a perfect summation of the evening. Luke Brooks opened his segment with a model wearing a chaotically hand-painted smock topped by a tattered headdress of the Olympic rings, timely enough in light of London 2012 except that it looked like it had been dredged from the depths of the ocean centuries after the event. Trailing skeins of wool, spattered finger daubs of crusted paint, rips, tears, and radical deconstruction (and more headdresses, including a vaguely accusatory "Old Hat" attached to—what else?—an old hat) compounded the confusion. But the chaos was breathtakingly crafted. And that was a reminder of why Saint Martins—and London's other fashion education institutions—have always been so vital to the health of the fashion industry worldwide.

The vision offered by the other L'Oréal winner, Craig Green, was poles apart in its precise monochrome layering, but it still had a melancholic out-of-time feel with clothes that implied a Middle Ages/Middle Eastern narrative of masters and servants. Or maybe that was simply because Green's last looks suggested men in full burkas, as provocative a comment on powerlessness as you could expect to find in a fashion show.