Wayne Teasdale was a lay monk who combines the traditions of Christianity and Hinduism in the way of Christian sannyasa. He was co-editor with George Cairns of The Community of Religions. He is convinced that interspirituality — "the sharing of ultimate experiences across traditions" — will be the religion of the third millennium. Teasdale further unpacks this term: "Interspirituality is a holistic understanding of the contemplative experience. It has room for all kinds of experiences, insights, methods of prayer and transformation. It values the experience of totality, intellectual vision, the way of pilgrimage, and forms of movement."

Some of the pioneers of this adventuresome and rewarding mystical path, one that includes both the way of contemplation and the way of action, are Bede Griffiths, Raimundo Panikkar, Thomas Merton, Rodger Kamenetz, and Thich Nhat Hahn. Teasdale goes on to spell out a few of the essential elements of interspirituality including solidarity with all living beings, deep nonviolence, humility, spiritual practice, mature self-knowledge, simplicity of life, selfless service and compassionate action, and the prophetic voice.

The Mystic Heart is a visionary work that presents a bold and imaginative glimpse of the fruits of multi-faith sharing and collaboration. As Beatrice Bruteau notes in the introduction, "Nothing is more practical for realizing our desire for a better world than mysticism." Teasdale's yearning for a universal communal spirituality that cuts across all traditions is one that we can celebrate. On these pages, he has presented stirring blueprints for global mysticism.