I found this book extremely helpful on mutiple levels. Beyond the fact that Mahayana Buddhism suffers from a lack of cohesive literature combined, Williams counters this problem in his gathering of doctrine and his own insight on the history, evolution, and spread of Mahayana. He shows great detail to the evolution of each "school" and how it was affected by the geographic, ethnic, and cultural environments that fomred each branches specifics.
A historical paper trail is fomed for many of the major works attributed to Mahayanist thought, so that we see roots formed. This grants immense clearity to many misunderstanding about certain school ideologies that might appear completely unrelated until all the details are shown within Williams book.
Although there are no actual sutras translated, the book is a perfect starting point for philosophies, history, and a listing of many of the great Mahayana sutras, which one could then find available to start forming an actual library for practice and reference.
As a Priest in the Pure Land tradition and trained in both Mahayana and Theravadin, this book stands apart in my findings of authors that spread knowledge in quanity and quality instead of minute chunks for only lineage lip service.
Mr. Williams has done a fantastic job of clearly and effectively laying down the foundations of the Mahayana movement. This movement, arguably the most colorful of the incarnations of Buddhist thought and theory, has a convoluted past, and Mr. Williams has expertly shown the reader the origins of the Mahayana and the origins of modern Buddhism. The only criticism that would in any way deter the reader from thinking this work to be one of the definitive in the doctrine is William's unfortunate tendency to mix his opinions which are for the most part religiously based, with philosophical quandries. Mr. Williams is the European Secretary for the International Association of Buddhist Studies, and I feel as such his opinion surfaces on several issues, most notably in the chapter on the Saddharmapundarika Sutra. The educated reader, or at least the reader able to assimilate William's position, can, however, easily overcome the minor references to academia based on faith rather than empirical knowledge. All minor biases aside, Mahayana Buddhism: The Doctrinal Foundations is a superior work when compared to many mainstream texts used in Buddhist study, which tend to be more esoteric, or treat only specific facets of the huge diaspora that spawned Buddhist practice in so many countries. Mr. Williams has produced a great work of fantastic merit in regards to understanding Mahayana Buddhism, and should be lauded for his work which makes, in my humble opinion, a stupendous read.