A long interruption from 1852 to 1864 which was the period of political reaction and at the same time that of the disappearance, the dispersion and the absorption of the old socialist schools, separates the International of the _Arbeiterbildungsverein_ of London, from the International properly so called, which, from 1864 to 1873, strove to put unity into the struggle of the proletariat of Europe and America. The action of the proletariat had other interruptions especially in France, and with the exception of Germany, from the dissolution of the International of glorious memory up to the new International which lives to-day through other means and which is developing in other ways, both of them adapted to the political situation in which we live, and based upon riper experience. But just as the survivors of those who in December, 1847, discussed and accepted the new doctrine, have re-appeared on the public scene in the great International, and later again in the new International, the Manifesto itself has also re-appeared little by little and has made the tour of the world in all the languages of the civilized countries, something which it promised to do but could not do at the time of its first appearance. There was our real point of departure; there were our real precursors. They marched before all the others, early in the day, with a step rapid but sure, over this exact road which we were to traverse and which we are traversing in reality. It is not proper to give the name of our precursors to those who followed ways which they later had to abandon, or to those who, to speak without metaphor, formulated doctrines and started movements, doubtless explicable by the times and circumstances of their birth, but which were later outgrown by the doctrine of critical communism, which is the theory of the proletarian revolution. This does not mean that these doctrines and these attempts were accidental, useless and superfluous phenomena. There is nothing irrational in the historic course of things because nothing comes into existence without reason, and thus there is nothing superfluous. We cannot even to-day arrive at a perfect understanding of critical communism without mentally retracing these doctrines and following the processes of their appearance and disappearance. In fact these doctrines have not only passed, they have been intrinsically outgrown both by reason of the change in the conditions of society and by reason of the more exact understanding of the laws upon which rest its formation and its process.