How Doctors Think - The Fallacy of Logic

The Fallacy of Logic

In a later chapter Groopman reports a frank discussion with Dr. James E. Lock, chief of cardiology at Boston Children's Hospital. During their conversation, Groopman asks the world-renowned cardiologist about the times in his career when he made mistakes in patient treatment.

To the query, Lock gives the cryptic response, "All my mistakes have the same things in common."

Lock then elaborates, discussing recommendations he made to repair specific heart defects in neonates that ultimately led to worse clinical outcomes and potentially avoidable deaths. The recommendations he made were based on a purely logical understanding of cardiac physiology. The crucial point of Lock's discussion came with his confession:

Impeccable logic doesn't always suffice. My mistake was that I reasoned from first principles when there was no prior experience. I turned out to be wrong because there are variables that you can't factor in until you actually do it. And you make the wrong recommendation, and the patient doesn't survive. I didn't leave enough room for what seems like minor effects--the small fluctuations in oxygen levels, which might amount to one or two or three percent but actually can signal major problems in the heart.... is very sound logic. But it's wrong...These children developed right heart failure and clinically they became worse. There are aspects to human biology and human physiology that you just can't predict. Deductive reasoning doesn't work for every case. Sherlock Holmes is a model detective, but human biology is not a theft or a murder where all the cues can add up neatly.

Groopman goes on to write, "Lock averted his gaze and his face fell; to be wrong about a child is a form of suffering unique to his profession ."