When Alex Wayman's article, entitled "Buddhism, Schools of: Esoteric Buddhism," appeared in the first edition of The Encyclopedia of Religion in 1987, the study of Tantric and esoteric forms of Buddhism was just beginning to emerge from the margins of Buddhist studies in general. Since that time, it has come to occupy (or at least to share) center stage in most special areas of Buddhist studies. Accordingly, a thorough overview of the study of Buddhist esotericism as it now stands is a desideratum, but one that could not be realized in time for the present publication. The following brief remarks, together with the additions to the bibliography, must in the event serve to offer the reader an orientation to the present state of the field.

Just what is Tantric Buddhism? Though several definitions have been proposed, none...