Tathagatagarbha -- Buddha Nature -- is a central concept of Mahayana Buddhism crucial to all the living practice traditions of Tibetan and Zen Buddhism. Its relationship to the concept of emptiness has been a subject of controversy for seven hundred years. Dr. Hookam's work investigates the divergent interpretations of these concepts and the way the Tibetan tradition is resolving them.

In particular she does this with reference to the only surviving Indian commentary on the Tathagatagarbha doctrine, the Ratnagotravibhaga. This text addresses itself directly to the issue of how to relate...