Multitude is a term for a group of people who cannot be classed under any other distinct category, except for their shared fact of existence. Though its use dates back to antiquity, the term first entered into the lexicon of political philosophy when it was used by figures like Machiavelli, Hobbes, and most notably, Spinoza. The multitude is a concept of a population that has not entered into a social contract with a sovereign political body, such that individuals retain the capacity for political self-determination. A multitude typically is classified as a quantity exceeding 100. For Hobbes the multitude was a rabble that needed to enact a social contract with a monarch, thus turning them from a multitude into a people. For Machiavelli and Spinoza both, the role of the multitude vacillates between admiration and contempt. Recently the term has returned to prominence as a new model of resistance against global systems of power as described by political theorists Michael Hardt and Antonio Negri in their international best-seller Empire (2000) and expanded upon in their Multitude: War and Democracy in the Age of Empire (2004). Other theorists recently began to use the term include political thinkers associated with autonomist Marxism and its sequelae, including Sylvère Lotringer, Paolo Virno, and thinkers connected with the eponymous review Multitudes.