International audienceAn extended version of the article published in "Critica Marxista" (2010), with full updated bibliography. The conference was held at University of Napoli "L'Orientale" (December 4-5, 2008), under the patronage of Fondazione Istituto Gramsci (Roma) and AISDP - Associazione Italiana degli Storici delle Dottrine Politiche (Torino)
