The assertion that “sunlight is the best disinfectant,” sometimes stated as “light disinfects,” is so common on the contemporary Internet that it often goes without saying. It’s just true, no argument is needed. When someone does situate the term, the attribution invariably goes to Supreme Court Justice Louis Brandeis, who in 1913 wrote that “sunlight is said to be the best of disinfectants; electric light the most efficient policeman.”1 Although Justice Brandeis was describing how transparency and regulation can minimize financial crimes, the phrase “sunlight disinfects” resonated far outside the specific context of finance. It has since become a widespread aphorism, one that, according to The American Prospect’s Mark Schmitt, very quickly transcended insight “to cliché and beyond.”2
Reflecting on the ubiquity of the idea within the news media, Vox Editor-at-Large Ezra Klein links the sunlight model to journalists’ fundamental duty to inform. 3 According to this model, we have to call attention to harmful things like mass shootings, white supremacy, and everyday presidential racism, if we hope to do anything about them.