Karel Kos?k (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 Kos?k's philosophy to English-speaking readers, we show that Kos?k's work is important not only as a leading intellectual document of the Prague Spring, but also...