The moment at which they enter into the past, that is to say, that at which they are intrinsically outgrown, is precisely that of the appearance of the Manifesto. As the first index of the genesis of modern socialism, this writing, which gives only the most general and the most easily accessible features of its teaching, bears within itself traces of the historic field within which it is born, which was that of France, England and Germany. Its field for propaganda and diffusion has since become wider and wider, and it is henceforth as vast as the civilized world. In all countries in which the tendency to communism has developed through antagonisms under aspects different but every day more evident between the bourgeoisie and the proletariat, the process of its first formation is wholly or partly repeated over and over. The proletarian parties which are formed little by little have traversed anew the stages of formation which their precursors traversed at first; but this process has become from country to country and from year to year always more rapid by reason of the greater evidence, the pressing necessity and energy of the antagonisms, and because it is easier to assimilate a doctrine and a tendency than to create both for the first time. Our co-workers of 50 years ago were also from this point of view international, since by their example they started the proletariat of the different nations upon the general march which labor must accomplish. But the perfect theoretical knowledge of socialism to-day, as before, and as it always will be, lies in the understanding of its historic necessity, that is to say, in the consciousness of the manner of its genesis; and this is precisely reflected, as in a limited field of observation and in a hasty example, in the formation of the Manifesto. It was intended for a weapon of war and thus it bears upon its own exterior the traces of its origin. It contains more substantial declarations than demonstrations. The demonstration rests entirely in the imperative force of its necessity. But we may retrace the process of this formation and to retrace it is to understand truly the doctrine of the Manifesto. There is an analysis which while separating in theory the factors of an organism destroys them in so far as they are elements contributing to the unity of the whole. But there is another analysis, and this alone permits us to understand history, which only distinguishes and separates the elements to find again in them the objective necessity of their co-operation toward the total result.