Political parties are taken for granted today, but how was the idea of party viewed in the eighteenth century, when core components of modern, representative politics were trialled? From Bolingbroke to Burke, political thinkers regarded party as a fundamental concept of politics, especially in the parliamentary system of Great Britain. The paradox of party was best formulated by David Hume: while parties often threatened the total dissolution of the government, they were also the source of life and vigor in modern politics. In the eighteenth century, party was usually understood as a set of flexible and evolving principles, associated with names and traditions, which categorized and managed political actors, voters, and commentators. In The Persistence of Party: Ideas of Harmonious Discord in Eighteenth-Century Britain (Cambridge University Press, 2021), Max Skjönsberg demonstrates that the idea of party as ideological unity is not purely a nineteenth- or twentieth-century phenomenon but can be traced to the eighteenth century.