In developing this argument, Friedman drew on Frank Knight’s aphorism that “business is business,” which Knight had defi ned as meaning that “business is one thing, and ‘charity’ another.” Knight, however, had accompanied that statement with a series of characteristic caveats: it assumed mutual free consent, which precluded the modes of persuasion often adopted in advertising; public engagement and oversight would be necessary to avoid externalities; and the pursuit of profi ts “must be sometimes seasoned with mercy.”

Angus Burgin, The Great Persuasion, loc. 478