"If we cannot carry our practice into sleep," Tenzin Wangyal Rinpoche writes, "if we lose ourselves every night, what chance do we have to be aware when death comes? Look to your experience in dreams to know how you will fare in death. Look to your experience of sleep to discover whether or not you are truly awake."
This book gives detailed instruction for dream yoga, including foundational practices done during the day. In the Tibetan tradition, the ability to dream lucidly is not an end in itself, rather it provides an additional context in which one can engage in advanced and effective practices to achieve liberation.
Dream yoga is followed by sleep yoga, also known as the yoga of clear light. It is a more advanced practice, similar to the most secret Tibetan practices. The goal is to remain awake during deep sleep when the gross conceptual mind and the operation of the senses cease. Most Westerners do not even consider this depth of awareness a possibility, yet it is well known in Tibetan Buddhist and Bon spiritual traditions.
The result of these practices is greater happiness and freedom in both our waking and dreaming states. The Tibetan Yogas of Dream and Sleep imparts powerful methods for progressing along the path to liberation.