As never since the first advent of production of commodities there has been such a fundamental revolution, it must necessarily be accompanied by an equally fundamental spiritual revolution. This economic revolution is the conclusion of the long period of class antagonisms and of production of commodities; it carries with it the end of the dualist and supernatural thoughts arising from this source. The mystery of social processes passes away with this period, and the spiritual expression of these mysteries must necessarily disappear with it. The slow development of human thought from ignorance to an ever increased understanding thereby ends its first chapter. This signifies the completion and conclusion of philosophy, which is equivalent to saying that philosophy as such passes out of existence, while its place is taken by the science of the human mind, a part of natural science. A new system of production sheds its light into the minds of men already before it has fully materialized. The same science which teaches us to understand and thereby to control the social forces, also unfetters the mind from the bewitching effects of those forces. It enables him even now already to emancipate himself from traditional superstitions and ideas which were formerly the expression of things unknown. We may anticipate with our mind the coming time. And thus the ideas which will then dominate are already even now growing within us in a rudimentary form corresponding to the present actual economic development. By this means we are even now enabled to overcome the capitalist philosophy in thought and to soberly and clearly grasp the matter-dependent nature of our spirit. The completion and the end of philosophy need not wait for the realization of socialist production. The new understanding does not fall from heaven like a meteor. It develops with the social-economic development, first imperfectly and imperceptibly, in a few thinkers who most strongly feel the breath of the approaching time. With the growth of the science of sociology and with that of its practical application, the socialist labor movement, the new understanding simultaneously spreads and gains ground step by step, waging a relentless battle against the traditional ideas to which the ruling classes are clinging. This struggle is the mental companion of the social class struggle. ************