Last year, I spent two weeks at a maternity and pediatrics hospital in South Sudan, where I now work full-time. During just those weeks, I signed death certificates for five children after unsuccessfully attempting resuscitation. As I was giving chest compressions to the first child, I fought back tears. She was about the size of my daughter.

In the United States, only 1 child in 100 dies before his fifth birthday. In South Sudan, it’s more like 1 in 10. What makes the difference?

Not parental love, that’s certain. The children who died under my care had parents who had tried to provide for their children as best as they could. The parents’ grief was as deep as mine would have been. And while medical care obviously makes a difference in individual cases, all these parents had managed to get to a doctor: me. I had access, in turn, to a reasonable supply of medicine and equipment—certainly equivalent to what many US physicians had a generation or two ago.

Every death certificate includes the cause of death. But the deeper causes of these children’s deaths wouldn’t fit in a box on a form. What was wrong had less to do with their individual health than with public health: the structures and environmental factors that many of us in the modern world can take for granted.

In a country like South Sudan, public health asks: Can your family access clean water? If you get sick from the water you drink, are the roads to the hospital safe enough for you to drive there in time? Is there a health professional who is trained well enough to give you the treatment you need? Can you afford the treatment? These are questions about government, policy, and institutions, not primarily about individual choice or circumstances.

The difference in public health between countries can be stark. But it’s nearly as dramatic within countries, including in the United States. The average life expectancy in some neighborhoods in Baltimore is 20 years lower than in neighborhoods one mile away. Here, the relevant questions take different forms: If you want to eat fresh produce, can you buy it within walking distance? If you are renting a house, how do you know lead paint in the walls isn’t poisoning your kids? If you’re coming home from prison, can you find a job—other than dealing drugs—that allows you to pay the rent?

In the Bible, especially in the Law that governed God’s chosen people, we find a relentless concern for public health. The Levitical code addressed not just individual and family matters but also communal ones: how animals were fenced, how food was harvested, and how people were allowed to rest.

All too often, I find that my fellow Christians in the West reflexively think about individual choices more than about the systems that shape those choices. Sometimes we get it right; concern for structures has motivated Christians’ engagement on policies about marriage, abortion, and euthanasia. But when it comes to the moral ecology that causes many of our neighbors to suffer from illness, addiction, and violence, we seem to think people will make the right choice if we just teach them to make it.

In fact, all of us make personal choices only within broader systems that either frustrate our best intentions or enable us to choose well.

Building and maintaining those systems requires careful choices about power. In order to help most people live longer, healthier lives, often a new rule has to be applied to everyone, or money from everyone (in the form of taxes) has to be spent. Enforcing good intentions via government power can be dangerous. But avoiding public policy doesn’t help anyone. Instead, we have to work at every level—individual, family, community, and nation—to apply the right power in the right places.

Public health is the discipline of thinking beyond our individual needs—especially if the systems around us work pretty well—and applying wisdom and resources on behalf of persons for whom the system is clearly not working. It’s not easy work. But when the alternative is a death certificate signed far too soon, it’s worth learning to do it well.

Matthew Loftus teaches health workers and practices family medicine in South Sudan with his family (MatthewandMaggie.org).

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