Antonio Gramsci, the Italian socialist born in Sardinia, founded the Italian Communist Party in 1921. He turned from political action to philosophical study when the Fascists jailed him in 1926 in order, said the public prosecutor, "to stop that brain working for twenty years." That brain, one of the most gifted that communism has produced, could not be stopped even by the inhuman conditions of Benito Mussolini's prisons: Gramsci filled three thousand pages with writing on a vast range of philosophical and political subjects. His frail health undermined by ill treatment, he died in Rome a week after his commuted term ended.

From the thirty-two prison notebooks, devoted editors have extracted "books" by grouping fragments on connected topics. In addition, L'ordine nuovo (1954) is a collection of articles from a socialist newspaper of that name, Letteratura e vita nazionale (1950) contains book and drama reviews, and Lettere dal...