The book elaborates Tibetan Buddhist teaching on the journey of the consciousness through the three stages, or bardos, of dying; the moment of death, the intermediate state between death and rebirth, and the process of rebirth itself. Central to the text is the belief that death presents the greatest opportunity to gain liberation, and so to step off the endless wheel of suffering that is held to characterise worldly existence. The bardo states are accessible to everyone. Yet there is a subtle process involved in attaining all higher states of consciousness -- a kind of trying not to try -- which is embodied most clearly in the life of Tibet's great saint, Milarepa, who never uttered a word that did not come out in song and poetry. This delicacy of living is manifest also in Chinese Taoism.

Buddhist philosophy teaches that birth and death are not phenomena that occur only once in a human life; they are part of an uninterrupted process. Every instant something within us dies and something is reborn. The different bardos represent the different aspects of this process in our own lives. All of these states are in flux.

1. chikhai bardo: The experience of the primary clear light and the secondary clear light at the moment of death.
2. chonyd bardo: The state of psychic consciousness. Experiencing lights, sounds and rays. Seeing the peaceful deities and then the wrathful deities.
3. sidpa bardo: Visions of the world into which one's karma leads one to be born. Visions of males and females in sexual union. Feelings of attachment and repulsion. Choosing and entering the womb.
4. bsam-gtan bardo: The dream state.
5. skye-gnas bardo: The everyday waking consciousness of being born into the human world.

These bardo states refer to the mental processes of the soul during the periods of life and rebirth. Outside of one's own consciousness there still remains another reality to be explored. Entrance to this reality is attained by recognizing at any point that the images and apparitions of the bardo state are merely the projections of one's own consciousness.

In the sidpa bardo, before rebirth, there occurs a judgment of the good and bad deeds of the soul of the dead.

If thou neither prayest nor knowest how to meditate upon the Great Symbol nor upon any tutelary deity, the Good Genius, who was born simultaneously with thee, will come now and count out thy good deeds with white pebbles, and the Evil Genius, who was born simultaneously with thee, will come and count out thy evil deeds with black pebbles. Thereupon, thou wilt be greatly frightened, awed, and terrified, and wilt tremble; and thou wilt, attempt to tell lies, saying "I have not committed any evil deed."

Then the Lord of Death will say, "I will consult the Mirror of Karma."

So saying, he will look in the Mirror, wherein every good and evil act is vividly reflected. Lying will be of no avail.

This situation very closely parallels the weighing of the heart described in the Egyptian Book of the Dead as well as the judgments appearing in later Greek and Christian traditions. It seems to reflect an archetypal reality that permeates the deep consciousness of many cultures, perhaps the ultimate symbol of meaning and order in the universe. Modern research is still attempting to investigate this reality, though perhaps with less sophistication than the Tibetans who claim to have developed ways to communicate with the departed spirit after death in order to aid in its passing through the bardo states.