The cliche is cathartic

They're already calling him the next James Dean. They said the same about River Phoenix, when he collapsed from a drug overdose in 1993, even though Dean died in a car race. The cumulative glamour of beauty and self-destruction was overpowering and transformative. It turned them into tragic heroes. Almost as soon as the first reports of Heath Ledger's untimely death emerged on Tuesday night, that process was under way, a collective outpouring of grief for another golden boy, talented, handsome - and gone.

The lure of cliche is intense, partly because we develop formulas and rituals precisely so that they can do our thinking for us in moments of shock or grief. Moreover, there is a comfort in collectivity: we are social beings, and it is reassuring to know our feelings are shared. The triteness of an expression does not preclude it from expressing a truth.

Most of us didn't know Ledger, Dean or Phoenix. Or Rudolph Valentino, Marilyn Monroe, Janis Joplin, Evita Perón or Princess Diana. And yet thousands seem to have loved them - if impassioned, even hysterical, mourning is a measure of love. Most of them didn't live heroic, or even exemplary, lives. But they pass the acid test: they were easy to identify with. Beautiful but all-too vulnerable, they express fragility and power at the same time, and we displace all kinds of emotion on to them. It was their job to make us do so.

It's no accident that these icons of glamour and loss were all performers (yes, that categorically includes Evita and Diana). Actors tell our stories for us and help us feel: sometimes they feel on our behalf, at other times they catalyse our own emotions. Aristotle understood this when he developed his idea of catharsis, that we might collectively undergo purging feelings of grief and loss by watching a tragic hero come to an untimely end because of a fatal error. Today we watch it in hypermediated real life, and experience the same feelings. Many will accuse those mourning Ledger of self-indulgence and ersatz emotionalism. But there is a more generous side to our shock - and, naturally, there is a familiar line ready to express it: any man's death diminishes us, because we are part of mankind.

Sarah Churchwell, a senior lecturer in American literature and culture at the University of East Anglia.