in reality control. Freedom, therefore, consists in mastery over ourselves and external nature founded upon knowledge of the necessities of nature, it is. therefore, necessarily a product of historical development. The first human beings to become differentiated from the lower animals were in all essentials as devoid of freedom as these animals themselves but each step in human development was a step towards freedom. At the threshold of human history stands the discovery of the transformation of mechanical motion in heat, the generation of fire by friction; at the close of development up to the present stands the discovery of the transformation of heat into mechanical motion, the steam engine. In spite of the tremendous revolution in the direction of freedom which the steam engine has produced in society it is not yet half complete. There is no question that the production of fire by friction still surpasses it as an agent in the liberation of humanity. Because the production of fire by friction for the first time gave man power over the forces of nature and separated him for ever from the lower animals. The steam engine can never bridge so wide a chasm. It appears however as the representative of all those productive forces by the help of which alone a state of society is rendered possible in which no class subjection or pain will be produced by reason of the lack of means for the sustenance of the individual, in which moreover it will be possible to speak of real human freedom as arising from living in accordance with the recognised laws of nature. But considering the youth of humanity it would be absurd to wash to impute any universal absolute validity to our present philosophical views, and it follows from the mere facts that the whole of history up to the present time is to be regarded as the history of the period extending from the time of
