On the Natural History of Destruction by W G Sebald, trans. Anthea Bell

In the best of causes, Allied bombers ignited the worst of calamities, as fire-storms incinerated German cities. Peter J Conradi pays tribute to a melancholy prophet who refused to let us forget

During the Second World War, vast formations of Lancasters, Halifaxes, Liberators and Flying Fortresses dropped a million tons of bombs on 131 German towns and cities, killing 600,000 and rendering 3.5 million homeless. Allied goals – destroying German industry, and breaking civilian morale – stayed unachieved. W G Sebald is concerned in these 1997 Zürich lectures with the immorality of carpet-bombing. He knows that Hitler was meeting a nemesis of his own devising.

But his main subject is in the inability of German writers to bear truthful witness. Sebald condemns their bad faith and selective amnesia, casting himself in the roles of public conscience and seer.

He loved King Lear's lament for Cordelia (quoted in his prose-poem After Nature): "What's dead is gone forever". One writerly task is to recover what's dead, to peer into the dark, to imagine the worst, to think the unthinkable; to remember. The destruction of Dresden provokes anguish: how can everyday language cope?

Sebald wants you to "see", and not forget: here are images to disturb both appetite and sleep. During Operation Gomorrah, the raid on Hamburg that started at 1am on 27 July 1943, 10,000 tons of explosive and incendiary bombs were dropped. Within minutes, 20sq km were alight, and the fire-storm – moving at 150kph – lifted roofs and gables, tore up trees and drove human beings before it like living torches before depositing them, roasted brown or purple and reduced to a third of their normal size, doubled up in pools of their own melted fat.

Records of autopsies ("heads and extremities could frequently be broken off without difficulty") are impressive. Casualty figures have never been agreed. A surviving mother – half-deranged with grief and shock – carried about in a suitcase the mummified remains of her child. Germans, who had proposed to "sanitise" all Europe, became themselves the rat people, ruled by rodents and "slippery finger- length maggots".

They fell first into lassitude and not-seeing, soon into wilful not-remembering.

There are corpses built into the foundations of the postwar German state whose "economic miracle" needed a destruction of outdated industrial complexes, and exploited the passive yet energetic workforce Nazism

had created.

"Sir, if a butcher tells you his heart bleeds for his country" – Samuel Johnson once said – "you may be sure he feels no uneasy sensation".W G Sebald, poet of discomfort, deplored facile un-earned feeling. He is after the real thing. Uneasy sensations are his kingdom.

He is a profoundly – and excitingly – unsettling writer. Believing that human history is a record of ever-intensifying disasters, he impersonates the coolly objective Messenger in classical tragedy, driven to tell you what no one wants to hear.

Sebald, like Freud, fears that what is repressed may be reenacted. He knows the risks of a pornography of violence, of voyeurism, and sado-masochism; and admires emotional understatement, abhorring melodrama, kitsch, hysteria and aesthetic pretension.

Three short essays on fellow writers end this collection. The reputation of morally compromised Alfred Andersch is targeted for selective destruction, while brave Peter Weiss and Jean Améry are commended for willingness to confront their own terror of the night, risking exhaustion on visits to places from which they may lack strength to return. Améry killed himself in 1974. The Gestapo had strung him up with his arms behind him, dislocated from their sockets, twisting uselessly over his head. His chaste, terrifying recollection satisfies Sebald's exacting requirements.

So much for the torment of remembering. What of the pleasures of reading? Born in 1944 into a peaceful pocket of Catholic Bavaria, Sebald settled willingly in the UK in 1970 and became a professor of German literature. Fluent in English, he still wrote in German. When he was killed by a car accident 15 months ago aged 57, we knew him as the exquisite, portentous and invigorating author of five brilliantly original and Teutonically gloomy works of fiction.

For Sebald everything is an uncanny memento mori: even a photograph is a device through which the dead scrutinise the living. He identified with the condition of solitary Jewish exiles (The Emigrants; Austerlitz), making poetry out of estrangement and grief. His Rings of Saturn grafts a walking-tour of Suffolk on to a thrillingly composed elegiac ramble around the mysteries of remembering and forgetting, the certainty of loss, the wicked cruelties of empire and war. Here is another context for Hitler's abominations: if Cromwell killed "half the population of Ireland" and Belgians in the Congo annually wasted 500,000 African lives, then genocide, too, has its "natural history".

Though the work of a laconically witty man, Sebald's writing has little humour. But his bleak pessimism, like Skegness air, is bracing. These four essays add to our picture of his achievement a fiercely didactic moralist, brave in his pursuit of truth.

Peter J Conradi's biography of Iris Murdoch is published by HarperCollins