You know, 97 percent of the time, if you come into a hospital, everything goes well. But three percent of the time, we have major complications.

We look for medicine to be an orderly field of knowledge and procedure. But it is not. It is an imperfect science, an enterprise of constantly changing knowledge, uncertain information, fallible individuals, and at the same time lives on the line. There is science in what we do, yes, but also habit, intuition, and sometimes plain old guessing. The gap between what we know and what we aim for persists. And this gap complicates everything we do.

Better is possible. It does not take genius. It takes diligence. It takes moral clarity. It takes ingenuity. And above all, it takes a willingness to try.

Good checklists, on the other hand are precise. They are efficient, to the point, and easy to use even in the most difficult situations. They do not try to spell out everything--a checklist cannot fly a plane. Instead, they provide reminders of only the most critical and important steps--the ones that even the highly skilled professional using them could miss. Good checklists are, above all, practical.

What is the alternative to understanding the complexity of the world?

I think the extreme complexity of medicine has become more than an individual clinician can handle. But not more than teams of clinicians can handle.

Outsiders tend to be the first to recognize the inadequacies of our social institutions. But, precisely because they are outsiders, they are usually in a poor position to fix them.