New ways to comprehend and control politics have been prophesied for the last half-millennium. Machiavelli blazed a ‘new route’ to traverse Renaissance statecraft. Hobbes constructed a new ‘civil science’ to pacify the revolutionary 1640s. Hume anticipated the novelty of the Enlightenment enterprise ‘to reduce politics to a science’. Adams conjured a ‘divine science of politics’ to consecrate a constitutional order without precedent. Hamilton heralded the ‘vast improvements’ and ‘wholly new discoveries’ in ‘the science of politics’ for post-revolutionary republics. Tocqueville foresaw ‘a new political science … for a world itself quite new’. The pattern continues into the third millennium, marking more than a century since the academic discipline of political science emerged in the 1880s. A ‘new science of politics’ was anticipated in the 1920s and 1930s, and was followed by a ‘behavioural revolution’ in the 1950s and 1960s. The conceptions of science backing these anticipatory ‘new’ schemes varied considerably, as did the political contexts within which they developed and the political projects to which they contributed.

The twentieth-century chapter in the venerable new science of politics is best understood, in its political dimensions, as a species of democratic theory, marked by increasingly technical methods and a healthy dose of realism about power, propaganda and public opinion. It is less famous than those grand ‘isms’ that have dominated twentieth-century political thought. But it intersects them, especially modernism, positivism, liberalism, socialism and fascism.