Anything written by John Blofield draws on the author's impressive and authoritaive knowledge of Eastern religions and philosophy, but the writing style can be a bit dry. This book is no exception, and is a very good general introduction to Tibetan Buddhism's tantric world view, thorough and reliable. This is an academic approach to to genuine tantra, and not the corrupted and misunderstood idea of tantra that has become common in the West. Recommended, as is pretty much anything that has been put out under Shambhala's imprint.