James Otis (1725–1783), a Massachusetts lawyer and Son of Liberty, was one of the most radical and articulate American pamphleteers. In his most famous pamphlet, The Rights of British Colonies Asserted, Otis claimed that American rights were based on the laws of nature and could not be erased by an oppressive monarch or a corrupt Parliament. Otis, whose sister Mercy Otis Warren was also an American propagandist, is credited with coining the phrase “No taxation without representation.”