The Italian thinker and politician Antonio Gramsci (1891–1937) was arrested in 1926 by Mussolini's fascist regime; the prosecutor told the court, "we must stop this brain from working for twenty years." In prison, as his health collapsed and under the eye of censorship, Gramsci wrote the famous "Prison Notebooks" — fragmentary, coded, yet among the most original texts of twentieth-century political thought.

Gramsci wrestled with a question: Marx had taken the workers' revolution to be inevitable; so why was there no revolution in the advanced countries of Western Europe, where on the contrary workers supported the very order that oppressed them? He found the answer in the concept of "hegemony." The ruling class does not maintain its power by state force alone (police, army, prison); above all it gets its own worldview accepted by the whole of society as "natural," "reasonable," "common sense," through culture, education, religion, media, and everyday language. People come to regard an order contrary to their own interests as ordinary, without question.

This was a rethinking of power: its most effective form is not force but consent. From here Gramsci's strategy of revolution also changes. Instead of a direct uprising (a "war of manoeuvre"), a long struggle in the cultural field ("war of position") is needed first; a new "common sense" must be built through intellectuals, schools, and civil society. In this context Gramsci argued that every social group creates its own "organic intellectuals."

The concept of hegemony reached far beyond the prison walls. Cultural studies, media theory, post-colonial thought, and contemporary political sociology are built largely on this insight of Gramsci's. That a thinker, in the very place he was jailed to be silenced, analysed the subtlest workings of power is one of the twentieth century's lasting ironies.