There are no signs of an end to it. No fewer than three sizeable new volumes by this prodigious Italian academic are currently on offer. There's a new novel - a bulky meaning-of-life enquiry about a shipwrecked nobleman in the 17th century. There's a bold work of linguistic philosophy, The Search for the Perfect Language (translated by James Fentress, Blackwell, pounds 20), which explores the history of the way the world speaks with reference to Genesis, Herodotus, Leibnitz, Swift, Dante, Bacon, Descartes, Locke, Vico and (of course) many others. And as if this weren't enough, there's a trendy volume of essays on mass market culture, in which Eco the journalist dishes out opinions on such subjects as the abuse of rhetoric, the meaning of Charlie Brown and La Cicciolina (Apocaplypse Postponed, edited by Robert Lumley, Flamingo, pounds 6.99).
Scholars are quick to find his scholarship a touch frivolous and are happy to put him down as - horror of horrors - a "populariser". Literary critics, meanwhile, can hardly resist finding his fictions too preoccupied with windy historical lectures to survive as exhilarating dramas. The latter, alas, will not want for ammunition when it comes to his new novel. A seafaring adventure crossed with a philosophical inquiry, it documents the last days of a European castaway called Roberto, who fetches up on board an empty ship just one tantalising mile from dry land. But the island might as well be on the other side of the world so far as Roberto is concerned: for one thing, he can't swim; and for another, it lies just the other side of the international dateline. Eco presents the time barrier as an obstacle every bit as palpable as the reef that lies between Roberto and safety. Those hills that seem so close are yesterday's hills (today they could be shrouded in mist); that great sunset is a product of yesterday's weather (today it could be pouring). Our hero is well equipped with telescopes - by a happy chance, the ship turns out to be virtually a floating research laboratory of 17th-century science. But he realises that to find out what is happening on the island he must wait until tomorrow. He is trapped, as it were, by time as well as space.
It is a nice idea, and we can see why Eco was attracted to it. As in The Name of the Rose, where a medieval Sherlock Holmes used his superior knowledge of logic and theology to hunt down a dark-age serial killer, Eco is able to ruminate, in the context of a life-or-death adventure, on the precariousness of human life and the arbitrary nature of human knowledge. But The Name of the Rose could afford to digress in a way that the new work cannot. There, we had a murderer on the loose, and each excursion into classical thought was pregnant with possible clues. Here, there is not quite so much at stake. Roberto spends more time reviewing his life - an admittedly colourful pageant of wars, sieges, courtly adventures in espionage and love - than he does on his own particular predicament. As a result, the book feels more than usually like an account of something that has already happened. There isn't a feeling that things could go either way: it is indeed a painted ship upon a painted ocean, and after a while the adventure itself (which begins brilliantly) feels notional. The world of thought takes such priority over the world of action that even when Roberto is taking his first ever swimming lesson, the emphasis is not on the experience itself, but on a long debate to do with the rotation of the stars.
Actually, the whole business about swimming is seriously rum. For some reason Roberto does not feel up to making a raft - the classic castaway solution. Instead, he laboriously learns to float. And here is what happens: "Two or three times he tried turning over, and he grasped a principle, indispensable to every swimmer, namely, when you have your head in the water, you must not breathe." It might be beyond the imagination of readers to believe that Roberto - who was adrift for two days on a plank before attaining the relative safety of the empty ship - needs to learn that you can't breathe under water.
The novel purports to be an examination of the journal kept by Roberto as he stares out from his lonely vantage point in the Pacific Ocean. As a narrative technique this is very appealing. It allows the author to skip over absurd coincidences and lulls in the story with a scholarly smile, and encourages the reader to speculate freely. But it is a method better suited to brief, succinct parables. Eco loves Borges and Calvino, and imitates their quizzical tone of voice and eye for insoluble conundrums. They, however, knew that brevity was the soul of this type of wit. Unfurled at Eco-length, the mysteries seem portentous. "The story is as clear as it is dark," he writes. "So here I am," he has Roberto think, "illuding myself with the illusion of an illusion." And so on.
At the end, after 500 pages of philosophising, Eco can't resist adding one of those what-does-it-all-mean epilogues in which he points out, pseudo- mishievously, that it is all meaningless anyway. Roberto's manuscript, he admits, might well be merely "mannered exercises." His experience leads him to the conclusion that he is insignificant - a trivial compound of stray atoms - and this leads him to a proper appreciation of his true love. But Eco swiftly subverts this by pointing out that Roberto "did not have the makings of a philosopher". It is a dashing gamble to insist that what we have just read is, more or less, a waste of time. Readers can be forgiven if they don't laugh.