The title Mountains Beyond Mountains comes from a Haitian proverb and is a metaphor for life’s challenges. Once you have scaled one mountain, you reach a place where you can see that there are always more mountains farther away: you will never stop climbing, never be finished. In the case of Paul Farmer, whose visionary spirit is the subject of this book, his mountain is the struggle to provide medical help to all desperately poor people. In fact, the man Tracy Kidder writes about in this nonfiction account is something of a secular saint, for Paul Farmer really only comes alive when he is tending to the illnesses of people the rest of the world has forgotten.

During the years chronicled in the book, Farmer crosses the globe many times, from his origins in the American South to his medical training at Harvard University, but he focuses his attention on some of the world’s most struggling people: the prison population in Russia, the slum dwellers of Lima, Peru, and, most especially, the rural poor of Haiti, who have a particularly intense grasp on his heart.

Mountains Beyond Mountains tells Farmer’s story but less for its own sake than as a way to understand what led this man to dedicate his entire life to solving health crises that everyone else seems willing to let stand. The book is informative, but Kidder also writes it as a kind of challenge, a challenge that can be summed up in three lines: Helping the suffering poor is possible. Paul Farmer is doing it. Why aren’t you?

As readers follow Farmer’s treatment of developing ideas and practices of public health, his gentle interactions with rural Haitians, his development of a private charity, and his attempts to change international medical policies, that challenge will always be echoing through their minds.