NIRVĀṆA. About twenty-five centuries ago in northern India, Siddhārtha Gautama achieved nirvāṇa. That event ultimately changed the spiritual character of much of Asia and, more recently, some of the West. That something indeed happened is an indisputable fact. Exactly what happened has been an object of speculation, analysis, and debate up to the present day.

Nirvāṇa is both a term and an ideal. As a Sanskrit word (nibbāna in Pali), it has been used by various religious groups in India, but it primarily refers to the spiritual goal in the Buddhist way of life. In the broadest sense, the word nirvāṇa is used in much the same way as the now standard English word enlightenment, a generic word literally translating no particular Asian technical term but used to designate any Buddhist notion of the...