Since the founding of the communist party in 1848, the physical organization of revolutionaries has passed through a series of organizational forms, in an evolution interrupted several times by ruinous degeneration, its very name has been abandoned. Then recovered by Bolshevism in 1918 and by the third international. In 1973 the party found itself in need of confronting it history, to confirm itself fully in the tradition of the communist left, the current which, having been founded in 1921 as the communist party of Italy (section of the communist international) was ousted and then expelled for its unwillingness to accept the methods and policies of Stalinism that were triumphant in the international. Nonetheless, in the hearts of our comrades it has always been a certainty that our party was the true and only continuer of Lenin's and the Bolsheviks' work. The study presented here is based on this conviction. Impersonal and collective like our works, it limits itself to ordering the writings of Lenin and occasionally of other Marxists, on the one hand, and the writings of the left and the unwritten rules of conduct and work of the party today, on the other.