Over the past century, there have been striking improvements in health across the earth, including among many of its poorest and initially least healthy people. In India and China, which together include more than one-third of the world's population, life expectancy has increased by more than twenty-five years since 1950. In China, life expectancy now stands at seventy-three years and trails that in Europe by only about three years. Those concerned about health have a great deal to celebrate.

The celebration is, however, spoiled by the glaring exceptions, which are clustered in sub-Saharan Africa, where life expectancies are typically in the forties and fifties. Hundreds of millions of individuals will have decades less of life than those who made better choices about where to be born, and their shorter lives will be burdened with more illnesses and disabilities. According to the World Health Report 2000, disability-adjusted life expectancy in Sierra Leone is under twenty-six!

Unlike the mass death and suffering caused by the 2010 earthquake in Haiti or the 2004 Indian Ocean tsunami, these global health inequalities seem to me, as to many others, not just a tragedy but also a moral outrage. What distinguishes the world's massive health inequalities from natural disasters is that the inequalities are up to us and consequently, unlike nature, subject to moral judgement. The forces of nature may do catastrophic harm, but they cannot do wrong. They are incapable of evil.