There are probably few people who will not, at some point, feel that they are running a losing race against Time.

But there are fewer still who will do something creative with that notion - and by creative I do not mean re-mortgaging the house to buy a Porsche. Philip Davenport, poet and curator of the "language art" exhibition The Dark Would, which opens today at Edinburgh's Summerhall, is one of the few.

"What happened was that I hit 50 and just had this very awful creeping sensation of time leaking away. I wanted to do something to halt that process or at least to mark it," he says. The poet-cum-artist, who started out writing poetry in "polite little books which never thrilled me that much", had begun making forays into the art world a decade previously, by fly-postering his work on the street.

"That was much more exciting, especially when I was chased by the police," he laughs. It was but a short step, then, to handwriting text on to apples or making poetry from overheard conversations. A short step, too, to realizing that his approach had a lot of similarities with practitioners working in contemporary art.

But it was the increased awareness of his own mortality, and a fascination with the way in which many people are beginning to live their lives virtually, that set him on the path to Summerhall. "We are all massively affected by this double life we lead," says Davenport, who admits he is himself "quite primitive - I like things that are handwritten". "We exist and we inscribe ourselves on these machines - fantastic, extraordinary things - but they take us away from our own bodies. No one knows what that means yet. I guess there will be a point where you can interface your own thinking with a machine…but what does that mean?"

To explore this somewhat terrifying idea, Davenport invited artist friends to contribute to an anthology. Artists such as Jenny Holzer and Richard Long, among many others, were asked to respond to the idea "of what it is to have a body, and then not have one any more." That anthology is the basis for The Dark Would.

Long has contributed two circular text works based on walks he did on Dartmoor in 1984 and in Africa. These will be exhibited in a long narrow room, in which visitors will walk from one to the other, making Time the third element, Davenport says.

In a series of dialogues between artists and writers of all ilks and eras, Stephane Mallarme is 'in conversation' with new work by Richard Wentworth, and a whole room is dedicated to a print out of Rob Fitterman's epic and powerful documentation of photo captions from the United States Holocaust Memorial Museum in Washington.

Davenport's own work will show alongside some Holzer posters from the 1970s, which were designed to be flyposted in New York, and posters from the May 1968 Paris student uprising, covered in quotes from the man who largely inspired the uprising, Guy Debord. "All three of us are having a conversation about uprising and insurrection. Even though one of us is dead," notes Davenport.

Elsewhere in this huge exhibition, artist Steve Emmerson will set up a rather less standard dialogue between the living and the dead in a work which locates five typewriters at the points of a pentagram to get visitors to "channel the spirit of William Blake". Emerson, who has been divining Blake for the past year, already has five pages of a poem "from" the long-dead poet, but is hoping that Summerhall visitors will get Blake to finish it off. "Some people really do enter a very strange mental terrain in these circumstances, and it's all recorded," adds Davenport.

And here, perhaps, is a kernel of hope for Davenport's own temporal worries. Time might run out, but art lives on. And if you go to the grave with your best lines, you can always hope that Emmerson conducts a seance to winkle them out.

The Dark Would, Summerhall, Edinburgh (0845 874 3000, until January 24