De Leonism in the context of "Industrial unionism"

Revolutionary socialism is a political philosophy, doctrine, and tradition within socialism that stresses the idea that a social revolution is necessary to bring about structural changes in society. More specifically, it is the view that revolution is a necessary precondition for transitioning from a capitalist to a socialist mode of production. Revolution is not necessarily defined as a violent insurrection; it is defined as a seizure of political power by mass movements of the working class so that the state is directly controlled or abolished by the working class as opposed to the capitalist class and its interests.

Revolutionary socialists believe such a state of affairs is a precondition for establishing socialism and orthodox Marxists believe it is inevitable but not predetermined. Revolutionary socialism encompasses multiple political and social movements that may define "revolution" differently from one another. These include movements based on orthodox Marxist theory such as De Leonism, impossibilism and Luxemburgism, as well as movements based on Leninism and the theory of vanguardist-led revolution such as the Stalinism, Maoism, Marxism–Leninism and Trotskyism. Revolutionary socialism also includes other Marxist, Marxist-inspired and non-Marxist movements such as those found in democratic socialism, revolutionary syndicalism, anarchism and social democracy.

Daniel De Leon (/dəˈliːɒn/; December 14, 1852 – May 11, 1914), alternatively spelled Daniel de León, was a Curaçao-born American socialist newspaper editor, politician, Marxist theoretician, and trade union organizer. He is regarded as the forefather of the idea of revolutionary industrial unionism and was the leading figure in the Socialist Labor Party of America from 1890 until the time of his death. De Leon was a co-founder of the Industrial Workers of the World and much of his ideas and philosophy contributed to the creations of Socialist Labor parties across the english-speaking world, including: Australia, the United Kingdom, Canada, and the Socialist Trade and Labor Alliance.