Presents the Nyingma-lineage understanding of valid cognition in Buddhism. Its core subject is the Buddhist view of the two truths—the relative truth of conventional appearances and the absolute truth of emptiness and buddha nature—and how the two truths are inseparable. The main questions posed are: How can we know the two truths and how can we be certain that our knowledge is accurate? 

This book may be the first in English to present the Nyingma-lineage understanding of valid cognition in Buddhism and in the Vajrayana in particular. The translation is a clear and concise primer on higher realization through valid cognition in Buddhist philosophy. It poses and answers the questions: How can we know the two truths—the relative truth of conventional appearances and the absolute trugh of emptiness and buddha nature—and how can we be certain our knowledge is accurate? It includes the sutra presentation of the two truths and the tantra teachings of the two truths as the purity and equality of all phenomena. It will give Westerners a solid foundation in valid cognition through direct perception and reasoning according to the traditional Indian treatises of Dharmakirti and Dignaga.

Khenchen Palden Sherab Rinpoche (1938–2010) was born in eastern Tibet. He received his early education at Gochen Monastery and his higher education as a khenpo at Riwoche Monastery. He and his family escaped from Tibet in 1960. In 1965 Khenchen Rinpoche was asked by H.H. Dudjom Rinpoche to represent the Nyingma lineage as a founding member of the Central University for Tibetan Studies in Sarnath, India, where Khenchen taught Buddhist philosophy for seventeen years.

In the early 1980s Khenchen Rinpoche moved to New York to work closely with  Dudjom Rinpoche, and in 1988 he and his brother Khenpo Tsewang Dongyal Rinpoche founded the Padmasambhava Buddhist Center, which has monasteries and dharma centers in the United States, India, and Russia. Khenchen Rinpoche wrote over thirty books in Tibetan and English.