The Doctor Who Mopped the Floors

In 2014, Dr. Paul Farmer — Harvard professor, MacArthur genius grant recipient, and world-renowned infectious disease specialist — was spotted mopping the floor of a clinic in rural Haiti. A visiting journalist asked why someone of his stature would do janitorial work. Farmer shrugged. "The floor was dirty. The patients deserved better." This was no publicity stunt. Farmer had spent three decades building Partners in Health, an organization that brought world-class medicine to the poorest communities on earth.…