The pervasive Buddhist practice of venerating images and relics of the Buddha, which Christian missionaries had considered idolatry, was de-emphasized. Traditional lines dividing monks and lay people were blurred. Important roles were restored to women. The fundamental Buddhist concern to bring an end to suffering now encompassed support for social justice, economic modernization and freedom from colonialism.

Central to modern Buddhism was meditation, an emphasis, Professor Lopez says, that ''marked one of the most extreme departures of modern Buddhism from previous forms,'' which had made meditation only one of many spiritual activities and not necessarily the highest, even within monastic institutions.

Meditation now became a practice recommended for everyone -- and also ''allowed modern Buddhism generally to dismiss the rituals of consecration, purification, expiation and exorcism so common throughout Asia as extraneous elements that had crept into the tradition,'' he writes.

The emergence of modern Buddhism, as Professor Lopez describes it, played out a little differently in each Buddhist land. It did not touch Tibetan Buddhism, for example, until the Dalai Lama left Tibet and interacted with a Western audience.

Professor Lopez also notes that this idea of periodically reforming Buddhism from inevitable decline by returning to its roots was found within the tradition itself. But a Westerner reading this history cannot help but think of another religious response to modernization, the Protestant Reformation, with its claim to restore a pure primitive Christianity, its emphasis on equality rather than hierarchy and its rejection of sacrament and ritual in favor of individual piety and introspection.

Protestant as well as Enlightenment ideals were of course very much part of the Western modernity that these Asian Buddhist thinkers were coming to terms with. After all, the British arrived in India, where Buddhism had begun and once flourished, centuries after it had died out there. So they found ''Buddhist texts, artifacts and stupas,'' Professor Lopez said in a phone conversation, ''but no Buddhists.''

Thus Buddhism, he said, was a screen on which Europeans could project many of their own notions: the British in India, for example, sometimes calling the Buddha the ''Luther of India'' because he had supposedly challenged the Vedic priesthood and its rituals just as Luther had the Catholic priesthood and its sacramentalism.