Italian Marxist theorist, journalist, and founding member of the Italian Communist Party, imprisoned by Mussolini in 1926 and held until shortly before his death eleven years later. He is the single most influential figure in what came to be called Western Marxism, and he produced his major work — thirty-odd notebooks of fragments on politics, culture, and history — in a prison cell, under censorship, using deliberately obscure vocabulary to slip his ideas past his jailers.
Gramsci's central concept is hegemony. Capitalist societies, he observed, are not held together mainly by police and bayonets; they persist because their values, common sense, habits of thought, and cultural institutions (schools, churches, newspapers, trade unions, popular entertainment) lead working people to accept the existing order as natural and legitimate. The dominant class rules not just through the state's coercive apparatus but through "civil society" — the whole dense web of cultural life. Revolution in the advanced West would therefore require a long "war of position" within culture, not just a decisive "war of manoeuvre" for state power on the Bolshevik model.
From this follows his theory of the "organic intellectual" — every social class develops its own thinkers who articulate its worldview — and his famous, mordant formula: "pessimism of the intellect, optimism of the will." His influence runs through the The Frankfurt School, British cultural studies, the New Left, subaltern studies, and essentially any contemporary left analysis that takes culture seriously.