Willard L. Johnson received his Ph.D. in Religious Studies from the University of Wisconsin in 1973. He is now a professor emeritus of San Diego State University, where he teaches world religions, primal religions, shamanism, Asian religions, and religious experience.

Thanissaro Bhikkhu (Geoffrey DeGraff) grew up in rural New York and Virginia, and was later ordained as a monk in Thailand in 1976. He trained for ten years under Ajaan Fuang Jotiko, a member of the Forest Tradition, until the latter's death in 1986. After returning to the States to help set up Metta Forest Monastery in 1991, he was made abbot of the monastery in 1993 and was formally made a preceptor in 1995. In addition to teaching at the monastery, he teaches regularly with the John Wayne Dhamma Center in Orange County, and the Barre Center of Buddhist Studies in Massachusetts. He is the author of The Mind Like Fire Unbound, The Buddhist Monastic Code, and The Wings to Awakening. He is also translator of a number of Thai meditation guides, including the complete writings of Ajahn Fuang's teacher, Ajahn Lee Dhammadharo.