In this book, His Holiness the Dalai Lama gives a commentary to not only Atisha's revolutionary work but also to Lines of Experience, a short text written by Lama Tsong Khapa, who was perhaps the greatest of all Tibetan lam-rim authors. In bringing together Atisha, Lama Tsong Khapa and His Holiness the Dalai Lama, this book offers readers one of the clearest and most authoritative expositions of the Tibetan Buddhist path ever published, and it is recommended for those at the beginning of the path, the middle and the end. This is the first time a major teaching by the Dalai Lama has been published for free distribution.