In spite of the common view of Buddhism as nondogmatic and tolerant, the historical record preserves many examples of Buddhist thinkers and movements that were banned as heretical or subversive. The San-chieh (Three Levels) was a popular and influential Chinese Buddhist movement during the Sui and T'ang periods, counting powerful statesmen, imperial princes, and even an empress, Empress Wu, among its patrons. In spite, or perhaps precisely because, of its proximity to power, the San-chieh movement ran afoul of the authorities and its teachings and texts were officially proscribed numerous times over a several-hundred-year history. Because of these suppressions San-chieh texts were lost and little information about its teachings or history is available. The present work, the first English study of the San-chieh movement, uses manuscripts discovered at Tun-huang to examine the doctrine and institutional practices of this movement in the larger context of Mahayana doctrine and practice.By viewing San-chieh in the context of Mahayana Buddhism, Hubbard reveals it to be far from heretical and thereby raises important questions about orthodoxy and canon in Buddhism. He shows that many of the hallmark ideas and practices of Chinese Buddhism find an early and unique expression in the San-chieh texts.