Immortality - literary immortality, that is, not the banal, fleshly kind - is a tricky customer, capricious, demanding and vague. The only consolation it offers the writer is the negative one, that he will never know for certain that he hasn't achieved it. My advice is, do it for the money and let posterity take care of itself.

On Tuesday, Radios 3 and 4 co-operated in an odd examination of the vagaries of literary immortality, based on the fact that this day, 3 June 1997, was Enoch Soames Day. Enoch Soames was a third-rate poet of the 1890s in a short story by Max Beerbohm, author of such slim volumes as Fungoids (the name suggests something of the quality of the poems, Soames explains: strange growths, natural and wild, yet exquisite and many-hued and full of poisons). His work goes unnoticed (as does Soames: he is a perfect non-entity), but he clings to the notion that posterity will reward him.

In the story, he sells his soul to the devil in return for the chance to go forward one century - to last Tuesday afternoon - to visit the British Museum Reading Room and see what posterity has made of him. He expects to find biographies, commentaries, new editions of his work; instead he finds one reference to himself, as a ridiculous character in a laboured satire by Max Beerbohm.

The occasion of his visit was marked by a dramatisation of the story, broadcast on Radio 4 at the very hour when Soames was supposed to be in the Reading Room; and by an almost live feature, The Ghost in the Reading Room, broadcast on Radio 3 in the evening.

On paper, this seemed a disproportionate reaction to a little-known 80- year-old squib. Eric Pringle's dramatisation was no more than efficient - the joke being too firmly based on the page to make the transition very convincingly - and there were some embarrassingly weak ironies and flat moments in David Benedictus and Tom Braun's walk round Beerbohm's London. The feature culminated with the appearance of an actor impersonating Soames in the Reading Room, to a cringe-making display of mock amazement.

So I wouldn't mention it at all, if it weren't that it's the kind of enterprise - self-consciously arty and thoroughly pointless - that public broadcasting exists, in part, to attempt; and if it hadn't brought home, under the jocose manner, the peculiar horror that being forgotten must hold when being remembered is your only reason for living. Just think of all the thousands of mute, inglorious Enoch Soameses there must have been; this was a surprisingly haunting ghost.

Journalists are, of course, not very interested in literary immortality. Generally speaking, a journalist has to reckon that anything he writes is going to be no more than kindling on the bonfire of the vanities - it might make a bit of a spark one second but the next it will have wafted off into thin air. If they make a deal with the devil, it's for them to be allowed to keep their heads down and be swiftly forgotten. (He doesn't demand a soul in return: just that they keep on with the job, since the multiplication of reading-matter does his work for him.)

Sometimes the pact breaks down and the journalist does get a place in history: Martin Bell being a recent example. His series on television journalism, The Truth is Our Currency, has just finished its delayed run (R4, Fri). It's been particularly interesting to hear it in the light of recent events at Tatton; and hearing his stubborn affirmation that journalists can only deal in truth, or they lose the trust of the public, leaves you in no doubt that he was the right man to front an anti-corruption campaign. Tatton's gain is, you feel, the BBC's loss.