To my spiritual masters, His Holiness the Dalai Lama, Kyapje Kangyur Rinpoche, and Kyapje Dilgo Khyentse Rinpoche, and all those who have opened my eyes to compassion.

To my mother, Yahne Le Toumelin, and to my sister Ève, who taught me altruism by example. To Christophe and Pauline André, accomplices in altruism.

To my scientific mentors and friends thanks to whom this book has some credibility: Daniel Batson, Richard Davidson, Paul Ekman, Paul Gilbert, Jane Goodall, Richard Layard, Antoine Lutz, Tania Singer, Dennis Snower, Frans de Waal, and all those who enlightened me on numerous points.

To my friends, fellow workers, and benefactors in the Karuna-Shechen Association, who put compassion into action through their contribution to over a hundred humanitarian projects.

To Raphaële Demandre, who never misses an opportunity to help those who are in need.

To those who have contributed so much to improving this book: Christian Bruyat, Marie Haeling, Carisse Busquet, and Françoise Delivet.

Finally, to all beings, who are altruism’s reason for existence.