Tal Ben-Shahar, PhD ’04, was 30,000 feet over the Atlantic Ocean, caught in the uncomfortable, sleepless reverie for which airplane seats seem specifically designed. His mind drifted to his work in positive psychology, which had yielded two best-selling books and one of the most popular undergraduate courses in Harvard’s history. He thought of all the fields of knowledge that contribute to happiness—psychology and neuroscience, yes, but also education, philosophy, economics, art, music, literature, and many others—and wondered: Why could students study all those subjects but not one that focused specifically on the goal toward which they all strived?