Back in 2005, when I was filming the documentary Facing Sudan , I flew to Philadelphia, rented a car, and drove to the New Jersey office of pediatrician Dr. Jerry Ehrlich. We had spoken only on the phone after I had found an article about his work in Darfur with Doctors Without Borders and he enthusiastically agreed to an interview. His office was small, covered in children’s drawings, notes and letters. A small man himself, with a slight haunch when he stood, Dr. Jerry was a giant of a human being. I was nervous, not knowing what to expect or even confident in what I was doing. Yet, in a matter of minutes — seconds perhaps — he put me at ease.   We set up in his office — the wood paneling the same as it had been when he opened his practice decades earlier, I imagine -- now with a spot made bare by the endless rubbing of his office chair against the wall. There was little room for the camera or the lights, but we made it work.  And Dr. Jerry told his story. Empathy, comp...