The second group of writers, the so-called "intellectuals" outside the syndicalist movement, have grouped themselves about the monthly _Le Mouvement Socialiste_, started in 1899 by M. Hubert Lagardelle, a member of the Socialist Party, and about the weekly _La Guerre Sociale_, of which Gustave Hervé is editor. _Le Mouvement Socialiste_ was at first a Socialist monthly review, but accentuated its sympathy for the syndicalists as time went on, and became an expressly revolutionary syndicalist organ in 1904. The _Mouvement Socialiste_ counted among its constant contributors down to 1910 M. Georges Sorel and Edouard Berth. These three writers, Sorel, Lagardelle, and Berth, have tried to systematize the ideas of revolutionary syndicalism and to put them on a philosophical and sociological basis. The most prolific of them and the one who has been proclaimed "the most profound thinker of the new school" is M. Georges Sorel. M. Georges Sorel has written on various subjects. Among the works from his pen are volumes on Socrates, on _The Historical System of Renan_, on _The Ruin of the Ancient World_, a number of articles on ethics and on various other topics. The works that bear on revolutionary syndicalism which alone can be here considered, are: _L'Avenir Socialiste des Syndicats_, _La Décomposition du Marxisme_, _Introduction à l'Économie Moderne_, _Les Illusions du Progrès_, _Réflexions sur la Violence_, and a number of articles in various periodicals. The works of M. Sorel on revolutionary syndicalism stretch over a period of ten to twelve years: _The Socialist Future of the Syndicats_ was written in 1897; the second edition of his _Reflections on Violence_ appeared in 1910. Within this period of time the thought of M. Sorel has not only steadily developed in scope but has also changed in many essential points. It would require a separate study to point out the changes and their significance. This is out of the question in this study. The salient points only of M. Sorel's theories will be treated here, therefore, without consideration of their place in the intellectual history of their author. M. Sorel has attached his theories to the ideas of Marx. Revolutionary syndicalism is to M. Sorel but the revival and further development of the fundamental ideas of Marx. The "new school" considers itself, therefore, "neo-Marxist," true to "the spirit" of Marx[154] though rejecting the current interpretations of Marx and completing the lacunae which it finds in Marx. This work of revision it considers indispensable because, on the one hand, Marx was not always "well inspired,"[155] and often harked back to the past instead of penetrating into the future; and because, on the other hand, Marx did not know all the facts that have now become known; Marx knew well the development of the bourgeoisie, but could not know the development of the labor movement which has become such a tremendous factor in social life.[156]