This books reconstructs the decade that led up to 1968, examining the topography of the Italian political left after 1956 when it became increasingly critical of left-wing parties and institutional unions. The study traces the reasons why the extra-parliamentary Italian Left was the first to explode in Europe and the last to expend its antagonism. The author directs particular attention to the Left's political and ideological universe, both inside and outside the Communist and Socialist parties. Italian text.