Some sort of ancient religious textbook for helping the dying die a spiritually-maximized death. An English translation of it was turned into a psychedelic "handbook" by a Harvard academic named Timothy Leary, and was, it would seem, the book John Lennon was reading when he wrote "I'm Only Sleeping" and "Tomorrow Never Knows", early examples of "fair use" in rock and roll.

The Tibetan Book of the Dead is one of the key scriptures in the Tibetan Buddhist belief system. It actually has nothing to do with Buddhism. The book deals entirely with local beliefs.

The book was originally written in Sanskrit, and it is called "BardoThötröl".

It is a guidebook for the process of death, known as the Bardo to Tibetans. A description of each stage of the Bardo, and eventually rebirth, is contained within its pages.

The book was meant to be read to someone who has just died, typically by a family member, student(if the deceased was a teacher), or close friend.

The Tibetan Book of the Dead is a Tantric Tibetan Buddhist text that acts as a metaphysical guide to the process of dying, death, and rebirth. This collection of text includes such works as ``The Art of Dying,'' the ``Sutra on Passing from One Existence to Another,'' the ``Sutra on Death and the Transmigration of Souls,'' the ``Sutra on Entering the Womb,'' ``Transition to the Otherworld,'' and a number of tantras.

This book represents a number of local Tibetan beliefs (not universal Buddhist ones), and is meant to be read to a recently deceased family member, student, or close friend. The Book of the Dead was also translated to English and other western languages, and made its way into pop culture with books like ``The Psychedelic Experience: A Manual Based on the Tibetan Book of the Dead'' by Timothy Leary (et al), which was influential on the life of popular musician John Lennon. This book has naturally had a significant effect on the metaphysics of Tibetan Buddhism, and also a lesser one on Western culture.

``One could refer to this book as `The Tibetan Book of Birth.' The book is not based on death as such, but on a completely different concept of death. It is a `Book of Space.' Space contains birth and death; space creates the environment in which to behave, breathe and act, it is the fundamental environment which provides the inspiration for the book.'' - Commentary on the Tibetan Book of the Dead by Chögyam Trungpa.