The book presents two treatises of the Third Karmapa with detailed commentaries on them by Jamgen Kongtrul, which form the basis of the Zhentong philosophical direction of the Kagyu and Rime traditions. The first work discusses in detail Zhentong's ideas about consciousness and its various aspects (ground consciousness, immediate mind , polluted mind, mental consciousness, etc.), and also talks about the essential distinction between consciousness and primordial awareness, about the ways of transforming the first into the second. The treatise “On the Essence of the Tathagata” is devoted to the basic issue of the Mahayana - the nature of the Buddha, which is originally present in all beings and is the basis of the path of realization.