Jeremy Hayward is the international education director of Shambhala Training. He is the author of Letters to Vanessa: On Love, Science, and Awareness in an Enchanted World and Shifting Worlds, Changing Minds: Where the Sciences and Buddhism Meet. He teaches warriorship retreats around the world. Francisco J. Varela, Ph.D., was Fondation de France Professor of Cognitive Science and Epistemology at the École Polytechnique and the Institute of Neuroscience of Paris. He is also the author of Principles of Biological Autonomy.