Chapter 14 begins with the story of an unnamed patient who went in for surgery at the Beth Israel Deaconess Medical Center in Boston in 2008. The hospital made the mistake of operating on the wrong side of the patient’s body. Such medical mistakes, says Schulz, once more raise the question of whether error is eradicable or inevitable. A paradox is found here, she explains, because trying to eradicate error relies on the assumption of its inevitability.

One illustration of systematic attempts to eliminate error is the corporate quality-control process called Six Sigma. The term stems from the Greek letter sigma (σ), which, in statistical analysis, represents the standard deviation from the norm. Any deviation, in the Six Sigma system, is undesirable, an error in manufacturing or in the end product. Companies that achieve Six Sigma have only 3.4 errors per million chances for error.

Such error-prevention strategies all begin with the acceptance that error will take place, so the possibility of mistakes is recognized, and techniques are in place to deal with their occurrence. Another element these strategies rely on is openness, such that errors are acknowledged in order to combat future mistakes.