Mahanirvana Tantra, Tantra of the Great Liberation is the best known of the Tantric scriptures. It was translated by Sir John Woodruffe (under the pseudonym 'Arthur Avalon'), one of the few Indologists to gain direct access to this obscure and secretive branch of Hinduism. Framed as a conversation between the god Shiva and goddess Shakti, this text describes the chakra, or subtle energy structure of the human body, ceremonies, yogic practices and mantras for meditation, and a summary of the Hindu laws (dharma) regarding sexual behavior. The Introduction in this book was later published as a separate book entitled - 'Introduction to Tantra Shastra'.