You want to ensure people can do it right 99 percent of time. When we have to fire one of our surgical trainees, it is never because they dont have the physical skills but because they dont have the moral skills - to practise and admit failure.

Culture matters. Of course, if physicians are rewarded or penalized for their service and results, the culture will change. But the key values we doctors are being pressed to embrace are humility, teamwork, and discipline.

Checklists turn out...to be among the basic tools of the quality and productivity revolution in aviation, engineering, construction - in virtually every field combining high risk and complexity. Checklists seem lowly and simplistic, but they help fill in for the gaps in our brains and between our brains.

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.

We always hope for the easy fix: the one simple change that will erase a problem in a stroke. But few things in life work this way. Instead, success requires making a hundred small steps go right - one after the other, no slipups, no goofs, everyone pitching in.

And in stories, endings matter.

We've created a multitrillion-dollar edifice for dispensing the medical equivalent of lottery tickets - and have only the rudiments of a system to prepare patients for the near certainty that those tickets will not win. Hope is not a plan, but hope is our plan.