T rHE French labor movement of 1871-79 has always been described as timid and conservative, rejecting revolutionary methods and goals in favor of class conciliation, trade-unionism, and the traditional French co-operative doctrine. In 1878 Jules Guesde began the intensive propaganda of Marxian socialism. Organized labor, according to the conventional account, performed a complete volte-face and, in 1879 at the congress of Marseilles, proclaimed the principles of modern socialism.' Such a portrayal is superficial and strangely static. It implies that there was no development in labor ideology from 1871 to 1878. Yet, it is unlikely that the workers accepted unchanged the co-operative system which had failed in the 1860's. Nor is it likely that the bloody repression of the proletarian Paris Commune failed to influence the ideas of the labor militants. The accounts of the socialist propaganda of 1878-79 do not make clear either the reason for its rapid success or the circumstances which largely explain the division of the French socialists into many sects after 1879. Hence the need for a critical study of the period. When the Franco-Prussian War broke out in 1870, there was