"Jules Guesde is one of the most prominent personalities of the French left and one of the most controversial. An indefatigable campaigner and brilliant orator, he is one of the first to introduce Marxist thought in France and to want to structure the working world through a political party in order to oppose capitalism. Despite his intransigence and his dogmatism, Jean Jaurès chose to ally with him. "Guesdism" was thus determining in the founding of the French Socialist Party and its vocabulary of the "class struggle" will mark all the twentieth century." --Translated from back cover