This affectionate but bleak portrait of life in rural China is the work of a scholar who has managed to arouse no small amount of controversy. In 1980, after spending a year studying a Chinese village near Canton, he made the motor trip into the hinterlands that is the subject of this book. The Chinese claimed -- falsely, he says -- that the trip was unauthorized and demanded that Stanford University, where he was studying toward a PhD in anthropology, deal with him "severely." This it did by expelling him from the doctoral program, an "effective disbarment from the scholarly profession of my choice."

Stanford's action, however arbitrary it may have been, did not succeed in silencing Mosher. In his first book, "Broken Earth," he wrote about the Chinese village in which he lived; now, in "Journey to the Forbidden China," he describes his "extensive motor trip into the heartland of South China," an area to all intents and purposes not seen by western tourists or journalists since the communist revolution. Riding in a van, accompanied only by his Chinese driver, Ming, he got a firsthand look at the life lived by the peasants who are the large majority of China's population.

What he saw was a society that remains in the 17th century at best, the Stone Age at worst. "Peasants in China remain trapped within the time warp of their valleys," he discovered. "Like European villagers in the Middle Ages, they live and die within a few miles of their birthplace, cut off from knowledge of the outside world. Like serfs beholden to the lord of their manor, they are in thrall to the totalitarian state, whose officials run every commune. And like slaves in ancient Greece, they are an exploited underclass, their labor the bulwark of the national economy."

Beginning at Canton and moving steadily into the mainland, Mosher's journey -- for which, he is at pains to emphasize, he had full authorization and all necessary papers -- took him from what passes in China for urbanity into a world that most westerners would have genuine difficulty comprehending, just as its residents would have equal difficulty comprehending theirs. It is a world of stoop labor, primitive huts, denuded land, a near-total absence of modern conveniences and an utter ignorance not merely of the world outside but of life elsewhere in China. This primitive condition is actively fostered by the national government, Mosher believes, as part of "the insidious and never-ending effort of an entrenched bureaucratic class to refine the traditional classes -- peasants, workers and officials -- into hereditary castes, and to assume total control over them."

What Mosher saw, especially as he got farther and farther away from the relatively civilized conditions of the coast, convinced him that there are two Chinas, the gap between which is unbridgeable. One is the China of the cities, a place of bureaucrats and workers; the other is rural China, the land of the peasants. "What widens class differences in China beyond all reason," he writes, "is that a baby's future occupation is fixed at birth, inherited from its parents, so that workers beget only workers, peasants beget only peasants." And notwithstanding the claims made on behalf of the Maoist revolution, "Change outside of the cities had been incremental rather than revolutionary, gradual improvements in the fabric of a life still strikingly primitive."

Notwithstanding the depressing conditions he witnessed, Mosher's trip was a considerable pleasure most of the way, and he describes it in an engaging fashion. He writes amusingly about China's road system, about his efforts to befriend various people he met along the way, about some of the more startling food and drink he encountered. He writes with particular admiration and affection about Ming, who "came close to being the perfect traveling companion," a "silent but friendly presence, never boring you with non sequiturs about the weather, places or people," a person with whom "it was possible to be by yourself, and yet not be lonely; to have company, yet not be distracted."

The trip took a sudden turn for the worse in the remote and mysterious Kweichow Province, where authorities unexpectedly decided that Mosher was traveling illegally and shipped him back to Canton by train; this was the beginning of the chain of events that finally led to his dismissal by Stanford. It is a business about which he seems to have every reason to be bitter, but he has not let it affect his view of China or the Chinese. Toward the former -- toward, more specifically, official China -- he is skeptical, even hostile; toward the latter he is respectful, solicitous and sympathetic. His fine book leaves little doubt that he is justified on all counts.