IT IS NOT too surprising to learn that the best-selling book in Italy last year was a translation: after all, even a popular chap like Umberto Eco can't usually hope to compete with the heavy artillery of Stephen King, Jackie Collins or Tom Clancy. Slightly more remarkable, however, is the news that the writer of this blockbuster trades neither in tough-talking thrills nor in sex and shopping; that he is not signed up to a multinational publishing house or to a killer agent; indeed, that he has been dead for more than two millennia. For the best-seller in question, which has shifted more than 1,300,000 units since being published last summer, is La Lettera sulla felicita, or Letter on Happiness, and its author is the ancient Greek philosopher Epicurus (c. 342-270 BC).

Even if one takes the charitable view that the Italian book-buying public has a far more healthy appetite for the classics than its British counterpart, this looks like an attack of high seriousness so sudden and intense as to verge on the supernatural. It would have been surprising enough had the Italians decided to mount a mass revival of one of their own classic authors - Petrarch, say, or Leopardi - or perhaps of some Premier League philosopher such as Plato or Aristotle.

After all, President Clinton's claim that the Meditations of Marcus Aurelius is his favourite book hasn't exactly set the American books fairs on fire for reprints. But even as Greek philosophers go, Epicurus is a pretty obscure figure, seldom given more than perfunctory treatment in histories of the subject, and long out of print in Britain save in the most scholarly editions - the last complete translation to appear here was Bailey's, in 1926.

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What on earth is happening in Italy, then? The Italians themselves haven't managed to agree on that one. Interpretations of the new Epicurus cult range from the contemptous via the bemused to the enraptured. Vittorio Spinazzolacorrect, Professor of Modern Italian Literature at the University of Milan, ascribes it primarily to 'phoney intellectualism' and 'snobismo, the sort of snobismo now common among readers which compells them to buy a slim volume from the pen of a recondite author'. The classicist Dario Del Corno takes a kindlier view: 'I think that Epicurus has taught the Italian people that there are more things to be found in the world than the ones they're offered by the mass media.'

Part of the solution to the new Epicurus enigma, however, lies not in philosophy but in economics. As Simonette Fiori of La Repubblica puts it: 'The one certainty is that the Philosopher of Samos (Epicurus was born in Samos, though he was an Athenian citizen and spent the productive years of his later life in Athens) would never have crossed the finishing line first under his own steam. This unforeseen Epicurus boom is the ingenious invention of one man: Marcello Baraghini.'

By this, Ms Fiori means that Marcello Baraghini is the head of a radical publishing house, Stampa Alternativa, which has recently disrupted the Italy's book trade with its innovative Millelire series of small books retailing, as their name implies, for 1,000 lire - or, in British terms, for about 50p. In a country where a standard paperback costs around pounds 8 or more, that's quite a bargain, and the Millelire books have been sellling like hot panettonecheck, often outstripping their rivals twentyfold or more.

It's a remarkable coup, and what's more, according to the BBC producer David Evans, who investigated Italy's Epicurus craze for The Late Show, the Millelire books came about pretty much by accident. 'It really happened because Stampa Alernativa was about to go bust. Baraghini and his colleagues had set the press up in the Sities as a sort of anarchist outfit - they'd publish things like the Kama Sutra, books on how to roll spliffs and that kind of thing. Baraghini was even jailed once, for publishing a pamphlet which drew attention to an old law which gave children the right to prosecute their parents for abuse - something which has made him a bit of a hero in recent years, when there's been more widespread acknowedgement of family violence.

'But a couple of years ago Stampa Alternativa found themselves in a real financial mess, so they asked bookshops who sold their books - they generally retailed for around two pounds - just to give away their remaining stock. The bookshops couldn't so that for reasons of accounting and so on, so Baraghini said, all right, in that case just sell them for 50 pence.' .

This opened the floodgates, and before too long other small publishers were bringing out bargain, supereconomici lists of their own. 'The supereconomici ', says Professor Spinazzola, 'have shown that when you knock down prices, the scope of the market grows enormously. This is an innovation you could compare to the 'Oscar Mondadori' paperbacks of the sixties (a series similar to the Penguin Classics). Big publishing houses simply won't be able to ignore it.'

Still, none of this is quite adequate to explain why it should be the Lettera sulla felicita which has proved to be Millelire's greatest hit, selling around 8,000 copies a week in bookshops and many times that figure on kiosks. In their attempts to pin down the peculiar appeal of Epicurus for modern Italy, pundits have invoked any number of different hypotheses. Some say that the philosopher endorses a move towards 'enlightened consumerism' which has given some Italian citizens their principal sense of enfranchisement in a period of political deadlock; others, that he seems to be condemning Italian materialism (a view that professional philosophers may find quaint, since in the technical sense of the term, Epicurus is the ancient world's most important materialist; indeed, Karl Marx wrote his doctoral thesis on Epicurus and Democritus.)

Cynics - the modern kind, that is, not the followers of Diogenes - have said that the real reason Epicurus is selling so well is because the Millelire edition has become a chic little stocking-filler to give away with the sugared almonds at weddings or on birthdays, or even, in one weird instance, at a funeral. ('Death means nothing to the wise', Epicurus says, 'since every good and every evil lies in sensation; but death is the absence of sensation.') Stripped of their context and offered up in what purists have described as a rather ropey translation, Epicurus's dense maxims can look horribly like simply feel-good bromides, about as substantial as Jonathan Livingstone Seagull or the Little Book of Hugs - a charge you could scarcely make against similar chunks from Hegel or Merleau-Ponty.

Yet if the new view of Epicurus's thought is vulgar and cliched, at least it is a more accurate cliche than the old view that his message was simply that the end of life was to eat, drink and be merry. Such caricatures of his doctrine of pleasure as merely an excuse for gluttony are of great vintage. Take, for example, an epigram by Richard Flecknoe from 1761:

An Epicure is one of those

No God besides his belly knows,

And who besides his Bill of Fare

Does for no other Scripture care . . .

Libels of this kind were commonplace in Epicurus's own day, and one purpose of his Letter to Menoeceus (the text which has been translated as Lettera sulla felicita) was to refute all the spiteful accusations:

'Thus when I say that pleasure is the goal of living' Epicrus writes,'I do not mean the pleasures of libertines or the pleasures inherent in positive enjoyment, as is supposed by some people who are ignorant of our teachings or disagree with them or interpret them perversely. I mean, on the contrary, the pleasure that consists in freedom from bodily pain and mental agitation. . . '

Sadly, not only has the philosopher's protesting voice been drowned out over the centuries, but quite a bit of our knowledge of Epicurean doctrines has had to be inferred from various attempts at refutation and dismissal by his opponents. Classical authorities such as Diogenes Laertius tell us that his literary output was vast, but very little remains of this work except for three letters - to Herodotus and Pythocles as well as the Menoeceus / felicita epistle - plus a slim gathering of sayings, the Leading Doctrines, and a clutch of aphorisms known as the Vatican Sayings (so called because they were found in 1888 in a manuscript held by the Vatican).

Epicurus's supposed masterpiece Peri Physeos (On Nature) is almost completely lost but for a few scraps and tatters unearthed at Herculaneum, their sense largely conjectural. Moreover, though he had many followers during the 700 years or so after his death, their works are in a similarly fragmentary state. Only one major Epicurean document, Lucretius's great philosophical poem De rerum naturae has surived largely intact.

What we do know about Epicurus is that he wrote and taught extensively on the nature of matter (and particularly on atoms and their laws of motion), on sensation, perception and the thory of knowledge, and that he attacked superstition and popular religion: 'The opinions held by most people about the gods are not true but fallacious, and state that terrible penalties are meted out to the evil and the greatest blessings to the good. . . '. At one level, the ethical teachings contained in the Letter to Menoeceus are not particularly hard to grasp; however, they only make full sense in the context of a far larger and more elaborate philosophical system.

Not that this reflection appears to bother Marcello Baraghini, who maintains that Epicurus's wisdom has woken his country up to 'a view of responsibility, a view of freedom - this is the sign of a new civil rights.' This is a curious reading, since academic commentators on Epicureanism have generally emphasised precisely its quality of its political indifference. In the words of one modern philosopher, Epicureanism 'was largely negative, escapist, self-protective and therapeutic.' Yet Mr Baraghini may be right in thinking that there is a link between the Epicurus cult and the political mood of his country: at a time when institutions are in such a state of crisis that a major party like the Christian Democrats can simply dissolve itself, how comforting to find an old sage who seems to be telling you that it's fine, indeed positively virtuous, to withdraw from civic involvement.

The final paradox of this whole strange story, though, is one which the philosopher himself might well have enjoyed. Among his other doctrines of moderation, Epicurus teaches indifference to riches: 'Poverty, when measured by the goals that nature has set, is great wealth, whereas unlimited wealth is great poverty.' And though the Lettera sulla felicita has sold in what one Italian commentator called 'stellar numbers', the profit margin on its sales is so small that Marcello Baragghini is still a man of quite modest means.

(Photograph omitted)