When Paul Farmer first went to Haiti in 1983, he was studying medicine and anthropology and hoping to become a doctor for the poor, perhaps in Africa. He eventually became America's most celebrated doctor for the poor, made famous by Pulitzer-prizewinning author Tracy Kidder in his 2003 book, Mountains Beyond Mountains: The Quest of Dr. Paul Farmer, a Man Who Would Cure the World.
But it wasn't until this spring--22 years later--that Farmer, now 46, made it to Africa. He was invited by the Clinton Foundation and the government of Rwanda to do for this tiny East African country, still trying...