In 1983, Peter completed a PhD in the philosophical psychology of the Madhyamika school of Mahayana Buddhism. His teachers included Lama Thubten Zopa Rinpoche, Geshe Thubten Loden, Geshe Lhundup Sopa, Namkhai Norbu Rinpoche and Sogyal Rinpoche. After nine years as a celibate monk, Peter handed back his ordination. As a post monastic, he embarked on an intensive exploration of Western forms of healing and therapy.
In 1986, he began offering adaptations of Mahayana wisdom to mental health professionals. His workshops integrated Buddhist nondual wisdom with an understanding of group dynamics. He subsequently founded the Center for Timeless Wisdom, a Californian nonprofit organization, which offers contemplative dialogues and retreats in Australia, USA, Europe, India and Israel.
In response to requests from the many mental health professionals who attended his workshops, Peter has taught the principles and practices for a nondual psychotherapy. He also offers individual counseling sessions to clients in many countries.
In 1998, he teamed up with Dr. Mantel (President of the Association Internationale de Psychiatrie Spirituelle) to organize the first-ever conference focusing on the contribution of nondual spiritual experience to psychotherapy. This took place at the Mt. Madonna, California. The Center for Timeless Wisdom continues to sponsor an annual conference on Nondual Wisdom and Psychotherapy, with the additional support of graduate schools such as Saybrook Institute, California Institute of Integral Studies, JFK University, the Association of Transpersonal Psychology and the Institute of Transpersonal Psychology.
Peter’s books include Radiant Mind – awakening the unconditioned awareness (Sounds True, 2007), The Ontology of the Middle Way (Kluwer, 1990), Reasoning into Reality (Wisdom Publications, 1994), Essential Wisdom Teachings (with Penny Fenner, Nicolas-Hays, 2001) and The Edge of Certainty: Paradoxes on the Buddhist Path (Nicolas-Hays, 2002). Sacred Mirror: Nondual Wisdom and Psychotherapy (Editor, Omega Books, 2003). His psychological essays have appeared in journals such as the Journal of Contemplative Psychotherapy, Revision, Journal of the International Association for Spiritual Psychiatry, Psychologia (Tokyo), and 3e millenaire (France).
Besides offering experiential workshops, Peter has given presentations of his work at institutions such as Stanford Medical School, Columbia University, Saybrook College, California Institute of Integral Studies and Naropa University.