Gawande begins the book’s first section, “Diligence,” by discussing one of the most important activities a doctor can do: handwashing. Cleanliness is so important that hospitals even have “infection control” units that “stop the spread of infection in the hospital” (13). Gawande notes that “each year, according to the U.S. Centers for Disease Control, two million Americans acquire an infection while they are in the hospital. Ninety thousand die of that infection” (14). This statistic serves to remind the reader of the small tasks doctors must do every day, and the large toll a small human error like forgetting to wash one’s hands can do.

He recounts the story of the Viennese obstetrician Ignac Semmelweis, who “famously deduced that, by not washing their hands consistently or well enough, doctors were themselves to blame” (15) for the spread of many diseases in hospitals. Although this seemed like an ingenious breakthrough, Semmelweis failed to test his theory through any kind of clinical study, and the draconian measures he used to enforce handwashing led many to ignore his warnings (16). Thus, while Semmelweis made the breakthrough, he didn't do enough diligence to ensure his Idea would be implemented.