Over decades of research, Buddhist scholars, historians, and translators have uncovered a wealth of information about the early history of the Buddha and his teachings. But students of Buddhism often struggle to reconcile the history of the dharma that’s been told and popularized by Buddhists themselves with the history that’s revealed in other sources, including Buddhist texts.

According to Donald S. Lopez, celebrated scholar of Buddhist and Tibetan studies, there are many questions that continue to perplex those seeking to tell the story of Buddhism in India. Lopez has zeroed in on four questions that are particularly consequential: When did the Buddha live? Why were the Mahayana sutras written? What are the origins of Buddhist tantra? And finally, why did Buddhism disappear from India?

Lopez sits down with Tricycle’s Editor-in-Chief James Shaheen to discuss these questions, offer some possible answers, and consider the larger significance of the investigation itself.