After training in biochemistry at the Institute Pasteur, Matthieu Ricard left science behind to move to the Himalayas and become a Buddhist monkā€”and to pursue happiness, both at a basic human level and as a subject of inquiry. His deep and scientifically tinged reflections on happiness and Buddhism have turned into several books, most recently Altruism: The Power of Compassion to Change Yourself and the World. He is also the founder of the Karuna-Shechen foundation, which brings medical help and education to people in Tibet, Nepal, India, and Bhutan.