I first came across Ballard when I was a teenager. He was a friend of my father's, and my father championed his early work, calling him "the brightest star in postwar SF" (all purists call science fiction SF, and have nothing but contempt for "sci fi"). Ballard was a beautiful man, with a marvellously full, resonant face and hot eyes, and talked in the cadences of extreme sarcasm with very heavy stresses - he wasn't being sarcastic, merely expressive. The friendship between the two did not survive Ballard's increasing interest in experimentalism, which my father always characterised as "buggering about with the reader". But I was always delighted to see Jim later on. Funnily enough, he was an unusually lovable man, despite the extraordinary weirdness of his imagination.

His imagination was formed by his wartime experience in Shanghai, where he was interned by the Japanese. He was 13 at the time and took to the life in the camp as he would "to a huge slum family". But it wasn't just the camp that formed him - it was the very low value attached to human life, something he saw throughout his childhood. He told me that he'd seen coolies beaten to death at a distance of five yards from where he was standing, and every morning as he was driven to school in an American limousine there were always fresh bodies lying in the street. Then came the Japanese. He said "people in the social democracies have no idea of the daily brutality of parts of the east. No they don't, actually. And it's as well that they don't."

It is interesting that his two most famous novels were both filmed: Empire of the Sun by Steven Spielberg (an essentially optimistic artist who is never afraid of dark historical themes), and Crash by David Cronenberg (a much darker artist himself, and one who specialises in filming unfilmable novels). Crash is the more typical of Ballard's novels. It is animated by an obsession with the sexuality of the road accident and reminds you that the word obsession derives from the Latin obsidere, which means "to lay siege to". Ballard is beleaguered by his obsessions. Mood and setting are identical in him. He had very little interest in human beings in the conventional sense (and no ear for dialogue); he is remorselessly visual.

Empire of the Sun - his greatest success - came as a kind of blow to his faithful admirers. This novel, which is utterly realistic, despite the bizarre settings and incidents, seemed a betrayal of the Ballard cult. The cultists felt that Empire (as he used to call it) showed how Ballard's imagination had been warped into such a funny shape. The novel was a naturalistic explanation of how his imagination got that way. For the cultists (not very logically), again, it was like the witch doctor revealing how he faked his magic.

Ballard began as a hardcore SF writer. His very early short stories, on familiar themes such as overpopulation, societal decay and so on, are as good as anything in the genre. But the genre couldn't hold him. There followed four novels of glazed apocalypse - The Wind from Nowhere (1961), The Drowned World (1962), The Drought (1964), The Crystal World (1966) - where the world was destroyed by wind, by water, by heat and by mineralisation. Then came his brutalist period, beginning in 1970 with The Atrocity Exhibition. Two stories from that book give the tone of the collection: "The Facelift of Princess Margaret" and "Why I Want to Fuck Ronald Reagan". Then the concrete-and-steel period extends itself with Crash (1973), Concrete Island (1974) and High-Rise (1975). The next period can again be evoked by another title: Myths of the Near Future (1982). He was still in this period when he died (despite the moving and beautiful memoir Miracles of Life, published last year). The last novels - including Cocaine Nights and Super Cannes - were about the violent atavism of corporate and ultra-priviledged enclaves in a different kind of near future.

Ballard brought to this all his shamanistic skills. He kept asking: what effect does the modern setting have on our psyches - the motion sculpture of the highways, the airport architecture, the culture of the shopping mall, pornography and technology? The answer to that question is a perversity that takes various mental forms, all of them extreme. When he broke away from rigid SF, Ballard said that he was rejecting outer space for "inner space". This has always been his arena. Ballard will be remembered as the most original English writer of the last century. He used to like saying that writers were "one-man teams" and needed the encouragement of the crowd (ie, their readers). But he will also be remembered as a one-man genre; no one else is remotely like him. He was a talisman. Very few Ballardians (who are almost all male) were foolish enough to emulate him. He was sui generis. What was influential, though, was the marvellous creaminess of his prose, and the weird and sudden expansions of his imagery.

Ballard was a great exponent of the Flaubertian line - that writers should be orderly and predictable in their lives, so that they can be savage and sinister in their work. He lived in a semi-detached in Shepperton, which might as well have been called "Dunroamin", and there was the tomato-red Ford Escort parked in its slot in the front garden. When I wrote a long profile of him in 1984, I arrived at 11 in the morning and his first words were "Whisky! Gin! Vodka!" He told me that "Crash freaks" from, say, the Sorbonne would visit him expecting to find a miasma of lysergic-acid and child abuse. But, in fact, what they found was a robustly rounded and amazingly cheerful, positively sunny - suburbanite. In 1964 his wife Mary died suddenly, on a family holiday, so Ballard raised their three children himself. To begin with he could only manage to do this by drinking a scotch every hour, starting at nine in the morning. It took him quite a while to push this back to six o'clock in the evening. I asked him was that difficult, and he said: "Difficult? It was like the Battle of Stalingrad." But everything suggests that he was an impeccable and adoring father.

The last time I saw Ballard, three or four years ago, was when my wife and I, together with Will Self and Deborah Orr, had dinner with him and his partner of 40 years, Claire Walsh. He revealed in the restaurant that he probably had "about two years to live". This was said with instinctive courage, but with all the melancholy to be expected from a man who loved life so passionately.