A brilliant annotated translation of Doelpopa Sherab Gyaltsen's Mountain Dharma that opens a masterpiece of the Jonang tradition to Western readers and presents Doelpopa's provocative ideas about a true, eternal, and established reality that still impact Buddhism today. The controversial master Dolpopa Sherab Gyaltsen shook Buddhist Tibet when he taught that an eternal enlightened essence, or buddha nature, exists in full form in all living beings. The ideas discussed in Mountain Dharma are still as provocative now as when Dolpopa first taught them, impacting Buddhism to this day. Dolpopa identified the ultimate with the buddha nature, or sugata essence, which he held to be eternal and not empty of self-nature. The buddha nature is perfect, with all its characteristics inherently present in all living beings. It is only the impermanent and temporary afflictions veiling the buddha nature that are empty of self-nature and must be removed through the practice of the path to allow it to manifest. Dolpopa establishes the validity of his theories with an ocean of quotations selected from Indian Buddhist scriptures and treatises of indisputable authority, showing us that the ultimate is a true, eternal, and established reality, empty merely of other relative phenomena.