TRENDS IN HISTORICAL WRITING are rhymed with changes in society and shifts in political mood. Start a Cold War, endanger an upper class, or give a voice to the poor, the historians wil come to see the past differently.

A keen interest in popular culture has been fashionable at the top of the historical profession for a few years now. The interest is linked to the writing of history "from below" -- an approach which rejects the study of privileged groups for the study of workers, peasants, poor people, women and ethnic minorities. In America the from-below school surfaced in response to the vocal pressures of disavantaged groups. In Europe the school has ties with working-class movements and sympathies with Third World aspirations.

But the new preoccupation with popular culture also relfects a late 20th-century worry over the prospects for humanity. Running scared, historians are turning with sympathy to the thinking and feeling of ordinary folk; thus a sudden blossoming in the historical study of popular culture. We have known what aristocrats and elite groups have thought about the world. The new question is, what did most people think and feel?

This question preoccupies Carlo Ginzburg, professor of history at the University of Bologna. In the The Cheese and the Worms , as in his previous writings on 16th-century Italy, he listens to the broken and mumbled speech of the humble. This time he hit on a chatty and indeed eloquent protagonist: Domenico Scandella (1532-1600), nicknamed Menocchio, a family man and miller by trade, but also occasionally a freelance carpenter, sawyer, mason, farmer and guitarist. Hailing from Montereale, a tiny hill town some 60 miles north of Venice, Menocchio blundered into a tangle of heresies, was denounced to the religious authorities, tried and eventually executed.

The details of the case reveal a gifted and lively spirit. Unlike many of his rustic compeers, Menocchio knew how to read and write. He was driven by curiosity, loved ideas and abstract argument, was treasurer of his parish church and town major at least once. But he was also proud of his intellect and alas for him, something of a big mouth. His first trial (1584) disclosed that he like to discuss his religious views with neighboring acquaintances and that he was ready to engage even his learned inquisitors in debate. He believed that the sacraments (for example baptism and communion) were merchandise; that original sin was bunk; that the Holy Spirit was to be found in heretics, Turks and Jews, as well as Christians; that parts of the Bible were mere human invention; that the Virgin Mary was no virgin; that Christ was a man; that the soul dies with the body; that God is everywhere; that the universe had its origin in chaos, from which "a mass formed -- just as cheese made out of milk -- and worms appeared in it, and theses were . . . God and the angels."

Now these were extrordinary ideas for a 16th-century miller, and Menocchio horrified his inquisitors. He was condemned to prison for life but pardoned after two years and confined to his native town, on condition that he cleave to orthodox ideas "and wear forever a penitential garment, the habitello , decorated with a cross." Thirteen years later, in 1599, and by now a widower, he was rearrested and tried as a relapsed heretic. He had not been able to leash his mind and quiet his tongue. His surviving children had rejected him as a disgrace to the family, but even now the local arm of the Inquisition shrank from imposing the death penalty, until Pope Clement VIII himself commanded it.

Professor Ginzburg has excavated a marvellous and melancholy tale. Lay readers should know that historical work of his high order requires formidable skills and dogged research in Italian archives, counted among the richest in the world. Have made his find, Ginzburg then faced a tricky question: where had Menocchio got his ideas? The trial proceedings show that he got them partly from books, including the Bible, several religious compilations, John Mandeville's Travels , Boccaccio's Decameron , and even possibly a translation of the Koran.

The miller, however, reworked ideas. He was influenced by word-of-mouth, an especially important source because his region, Friuli, had known Anabaptist and other heresies in the middle decades of the 16th century. But the pertinacious part of Ginzburg's analysis holds that, Menocchio's views were also shaped by a submerged oral culture, perhaps centuries old. Fragments of it bobbed up in his testimony, released apparently by his encounter with literacy. And what we discern is a peasant's picture of the world based upon an "elemental, instinctive materialism": a by-product of the land, of work, the seasons and the daily round of practical needs. This would explain why Menocchio sprinkled the philosophical parts of his testimony with concrete worms. It would explain why he compared God to a father, a gentleman, a lord, and a great captain; why he conceived of God as assigning tasks to "stewards" -- meaning angels and the Holy Spirit; and why, under interrogation, as an autodidact steeped in the tactile world of his oral culture, he was so easily trammeled in absurd contradictions.

Professor Ginzburg's discovery of Menocchio is a dazzling entry into the historical world of popular culture. And most of us, being democratically inclined, would doubtless agree with his suggestion, made in an unguarded ideological moment, that the true liberation of humanity may well depend upon our readiness to recapture the old oral culture of the many, that is, our past culture. But I regret to say that this has all the air of being a pipe dream. For strange thing is, despite all the resentments and impatience of the "from-below" schools of history, that we have yet to understand the highbrow culture of the past: to understand it, I mean, as an intoxicating enterprise that continues to do a devilishly artful job of concealing its political, social and economic underpinnings.