Tib., theg-pa rim dgu: nine vehicles
A Tibetan Classification of the Buddhist Teachings
A note on sources
In general, the "Nine Vehicles" as presented here is a classification of all systems of
spiritual teachings into nine paths or vehicles (Skt., yana;
Tib. theg-pa) that comes from the Nyingma
tradition; the oldest tradition of Tibetan Buddhism.
However, in order for readers to orient themselves more easily, I have also added a great number of terms for these teachings that come from other traditions. Also, one should keep in mind that not only the Nyingma, but Vajrayana in general, has a somewhat biased view of non-Vajrayana Buddhism and its schools; regarding its own teachings as more advanced (just as do most other religions). Thus, for example, the use of terms such as "Lesser Vehicle" for Hinayana.
The classification and terminology presented here has been collected from a great variety of sources; from more or less all of the works given in the accompanying bibliography. Mainly, however, I'm indebted to the works of Keith Dowman, John Myrdhin Reynolds, John Shane and Giuseppe Tucci; although these authors are not at all responsible for this specific presentation of mine.
Last not least, the reader should realize that different schools apply (slightly) different classifications, and regard some texts as more important than others. Exactly which of the major Buddhist Tantras belongs to which stage and group, is a question often debated among the different schools and one that varies from account to account. An extensive discussion of this "problem", but then from a Gelugpa point of view, is provided in mKhas grub-rje's (1385-1438) Fundamentals of Buddhist Tantras (translated by F. D. Lessing and A. Wayman).