This great paradox at the heart of Christian, and therefore Western, tradition is the subject of Elaine Pagels's brilliant new book, Adam, Eve, and the Serpent, a work that will prove a landmark of historical thought and profoundly affect all future interpretations of the historical meaning of Christianity.

The attitudes and values we associate with Christian tradition, particularly attitudes toward sexual matters, evolved in Western culture at a specific time--during the first four centuries of the common era, when the Christian movement, which had begun as a defiant sect, transformed itself into the religion of the Roman Empire. These attitudes had not previously existed in the Christian form they eventually took, and they represented a departure from both pagan practices and Jewish tradition.

Within a century of Jesus and Paul, the Christian churches, though widely divided on questions of practice and belief, all agreed that Christians must reject the Roman gods and refuse to reverence the emperors, who ruled in their name. For many of the leaders of the early church, freedom was the practical message of the gospel: freedom in its many forms, including freedom from tyrannical government, freedom from prevailing social and sexual customs, freedom from sexual desire, and freedom of the will--that is, self-mastery as a means to spiritual renewal.

For almost three hundred years, Christianity prospered and grew as an illegal sect whose members increasingly reflected the diverse interests of an ever more complex population. By the fourth century, as the Christian movement became more powerful, the emperor Constantine reversed the long-standing policy of persecution and himself became a Christian. In the century following these momentous conversions--of Constantine to Christianity and the church to a respected imperial institution--Christian teaching itself underwent a revolutionary change from a doctrine that celebrated human freedom to one that emphasized the universal bondage of original sin. It is this profoundly consequential transformation that is the subject of Elaine Pagels's monumental book.