Vajrayana, or Tantric Buddhism, has been described as the latest phase in the development and evolution of Buddhist thought. For a long time, Western scholars dismissed Vajrayana as the final “degenerate phase” of Buddhist thought. This attitude was due to the fact that these materialistic scholars had only a Christian or a secular way of seeing the world. They could appreciate ordinary Buddhism (Theravada, etc), seeing the Buddha as the Christ of the East teaching an essentially moral message, or as a sort of spiritual humanist; but when faced with a system of knowledge and practice that embraced all the magical and occult elements that Western rationalism had rejected centuries ago, could only explain it as some sort of degenerate end phase.

Fortunately, in more recent times other Westerners have studied Tantric Buddhism first hand, at the feet of actual Tibetan Masters, and so have a more mature appreciation and respect for that noble tradition. Indeed, if anything good has come out of the terrible Chinese invasion and oppression of the Tibetan homeland in the 2nd half of the 20th century, it has been that this has driven Tibetan lamas and teachers to the West, and encouraged them to spread their tradition among sympathetic Westerners.

via Vajrayana.