David Foster Wallace's death, at the age of 46, is a grotesque shock. He was still young, and still brilliant; his gargantuan novel, Infinite Jest, and his remarkable short stories, displayed a startling originality in an age of increasingly predictable literary gestures. He was a comic writer who could also incorporate tragedy, satire, horror and philosophical enquiry. He set the bar so dizzyingly high with each new piece of writing that I cannot imagine where he might next have taken his art; and it hurts that I will never know.

It's normal when a gifted artist passes away to reach for some off-the-peg hyperbole and easy tributes, and I find myself reaching for them too; "greatest writer of a generation" and so on. But at a time when superlatives are scattered so widely and freely for marketing reasons, it is difficult to take the debased coins and polish them up into something like their original value. That was a concern of Wallace's, too: how to restore to language a value and truthfulness eroded by irony, propaganda and self-interest.

Wallace really was that good. His style spawned imitators, fans and outraged (or bored) detractors. Byzantine sentences combined a neurotic hyper-attention to detail with anxious self-corrections and hesitations, in the edgy stammering surface of human speech. It created, as only great writing can, a space to think about language as well as its content, and to see freshly how inextricable they are. So, above all, his was an ethical style, pressed into the service of a greater truthfulness and affection, not a peacock display of mere cleverness or self-regard.

His essays - including journalistic assignments - combined proper research and observation with an argument undertaken in genuine curiosity. Wallace never poked mean fun at his subjects; he let them emerge, in their own light and language, and then asked the pertinent questions. There is something humbly self-deprecating yet friskily amused and confident about his approach. His article for Gourmet magazine, about the Maine Lobster festival, manages to cover vast amounts of philosophical ground, before confronting readers with genuine ethical difficulty: "Is your refusal to think about any of this the product of actual thought, or is it just that you don't even want to think about it? And if the latter, then why not? Do you ever think, even idly, about the possible reasons for your reluctance to think about it? I am not trying to bait anyone here - I am genuinely curious. After all, isn't being extra aware and attentive and thoughtful about one's food part of what distinguishes a real gourmet?"

His remarkable novel Infinite Jest (1,000 pages, 100 of them footnotes of a sort) demonstrated similar virtues. Its near-futuristic parody of an America in the grip of addiction - to drugs, alcohol, sport, sex, entertainment, and other things - employs the acrobatic stylistic manoeuvres of postmodernism in order to combat the merely playful and ironic gestures of postmodernism itself, which Wallace saw as being not at odds with modern commercial society, but utterly complicit in it. Every heartless tic of facetious ironised postmodernism is redeployed to capture the heartfelt loss and confusion of human beings. Beneath its comedy and fireworks, it is a novel about deep sadness, especially the sadness of families. (It is arguable that the template which enabled Dave Eggers to write A Heartbreaking Work of Staggering Genius was set by Wallace's own.)

There is always a danger, after a writer's early death, particularly when suicide is mentioned, that impertinent biographical questions - the how and the why - will overwhelm aesthetic ones; that the mythical figure of the tortured Romantic genius will stand in front of our proper relationship to the work.

All I know right now is this: that any premature death is the source of great sorrow, intensely so for family and friends; and that this morning I am experiencing bewildering emotions: grief, for a man I never knew except through his words; and loss, for the words which he did not have time to write.