Gaetano Mosca (April 1, 1858 Palermo, Italy – November 8, 1941 Rome, Italy) was an Italian political scientist, journalist and public servant. He is credited with developing the Theory of Elitism and the doctrine of the Political Class and is one of the three members constituting the Italian School of Elitists together with Vilfredo Pareto and Robert Michels.
In 1909 Mosca was elected to the Chamber of Deputies of Italy, in which he served until 1919. During this time, he served as Under-secretary for the Colonies from 1914 until 1916. In 1919, Mosca was nominated life senator of the Kingdom of Italy. He served actively in this capacity until 1926. During the Fascist dictatorship, Mosca retired to teach and research.
During this time, Mosca also worked as a political journalist for the Corriere della Sera of Milan (after 1901) and the Tribuna of Rome (from 1911 to 1921).
Mosca is most famous, however, for his works of political theory. These were Sulla teorica dei governi e sul governo parlamentare (Theory of Governments and Parliamentary Government), published in 1884; Elementi di scienza politica (The Ruling Class), published in 1896; and Storia delle dottrine politiche (History of Political Doctrines), published in 1936.
Mosca defined modern elites in term of their superior organisational skills. These organisational skills were especially useful in gaining political power in modern bureaucratic society. Nevertheless, Mosca's theory was more liberal than the elitist theory of, for example, Pareto, since in Mosca's conception, elites are not hereditary in nature and peoples from all classes of society can theoretically become "elite". He also adhered to the concept of "the circulation of elites," which is a dialectical theory of constant competition between elites, with one elite group replacing another repeatedly over time.