Karel Kosík (1926–2003) was one of the most remarkable Czech Marxist philosophers of the twentieth century. His reputation as a creative thinker is owed largely to his philosophical ‘blockbuster’ Dialectics of the Concrete, first published in Czechoslovakia in 1963. In reintroducing Kosík’s philosophy to English-speaking readers, we show that Kosík’s work is important not only as a leading intellectual document of the Prague Spring, but also as an original theoretical contribution with international impact that sheds light on the meaning of labour and praxis, cognition and economic structure, and revolution and the crises of modernity.