In the fifty years which separate us from the publication of the Manifesto the specialization and the complexity of the proletarian movement have become such that there is henceforth no mind capable of embracing it in its completeness, of understanding it in its details and grasping its real causes and exact relations. The single International, from 1864 to 1873, necessarily disappeared after it had fulfilled its task. The preliminary equalization of the general tendencies and of the ideas common and indispensable to all the proletariat, and no one can assume or will assume to re-constitute anything like it. Two causes, notably, contributed in a high degree to this specialization, this complexity of the proletarian movement. In many countries the bourgeoisie felt the need of putting an end in the interest of its own defense to some of the abuses which had arisen in consequence of the introduction of the industrial system. Thence arose labor legislation, or as it has been pompously called social legislation. This same bourgeoisie in its own interest or, under the pressure of circumstances has been obliged, in many countries to increase the generic conditions of liberty, and notably to extend the right of suffrage. These two circumstances have drawn the proletariat into the circle of daily political life. They have considerably increased its chance for action and the agility and suppleness thus acquired permit it to struggle with the bourgeoisie in elective assembles. And as the _processus_ of things determines the _processus_ of ideas, this practical multiform development of the proletariat is accompanied by a gradual development of the doctrines of critical communism, as well in the manner of understanding history or contemporary life as in the minute description of the most infinitesimal parts of economics: in a word, it has become a science. Have we not there, some ask, a deviation from the simple and imperative doctrine of the Manifesto? Others again say, have we not lost in intensity and precision what we have gained in extension and complexity? These questions, in my opinion, arise from an inexact conception of the present proletarian movement and an optical illusion as to the degree of energy and revolutionary valor of the former movements.