The possibilities and probabilities are all we have to work with in medicine, though. What we are drawn to in this imperfect science, what we in fact covet in our way, is the alterable moment-the fragile but crystalline opportunity for one's know-how, ability, or just gut instinct to change the course of another's life for the better.

The striking thing is that WHO doesn't really have the authority to do any of this. It can't tell governments what to do. It hires no vaccinators, distributes no vaccine. It is a small Geneva bureaucracy run by several hundred international delegates whose annual votes tell the organization what to do but not how to do it.…The only substantial resource that WHO has cultivated is information and expertise.

What is needed, however, isn't just that people working together be nice to each other. It is discipline. Discipline is hard--harder than trustworthiness and skill and perhaps even than selflessness. We are by nature flawed and inconstant creatures. We can't even keep from snacking between meals. We are not built for discipline. We are built for novelty and excitement, not for careful attention to detail. Discipline is something we have to work at.

The big thing that's happened is, in the time since the Affordable Care Act has been going on, our medical science has been advancing. We have now genomic data. We have the power of big data about what your living patterns are, what's happening in your body. Even your smartphone can collect data about your walking or your pulse or other things that could be incredibly meaningful in being able to predict whether you have disease coming in the future and help avert those problems.

In many ways, the effort to study philosophy was my rebellion away from medicine. I'm the son of two Indian immigrant physicians, so the natural path for me would have been to become a doctor. I ended up doing the master's degree at Oxford in politics, philosophy, and economics while already having a seat in medical school. I was keeping that as my escape hatch. But my hope was that I might become a philosopher or something else entirely.

Expertise is the mantra of modern medicine.

Our ideas of what our priorities are shift as we come face-to-face with some of the struggles.