Marx 's focus on the process of social change is so central to this thinking that it informs all his writings. The motor force of history for Marx is not to be found in any extra-human agency, be it "providence" or the "objective spirit." Marx insisted that men make their own history. Human history is the process through which men change themselves even as they pit themselves against nature to dominate it. In the course of their history men increasingly transform nature to make it better serve their own purposes. And, in the process of transforming nature, they transform themselves.
In contrast to all animals who can only passively adjust to nature 's requirements by finding a niche in the ecological order that allows them to subsist and develop, man is active in relation to his surroundings. He fashions tools with which to transform his natural habitat. Men "begin to distinguish themselves fro animals as soon as they begin to produce their means of subsistence. . . . In producing their means of subsistence men indirectly produce their actual material life."
Men "who every day remake their own life" in the process of production can do so only in association with others. This is what makes man a zoon politicon. The relations men establish with nature through their labor are reflected in their social relationships.
The production of life, both of one 's own by labor and of fresh life by procreation, appears at once as a double relationship, on the one hand as a natural, on the other as a social relationship. By social is meant the cooperation of several individuals, no matter under what conditions, in what manner or to what end. It follows from this that a determinate mode of production, or industrial stage, is always bound up with a determinate mode of cooperation, or social stage, and this mode of cooperation is itself a 'productive force. '
In their struggle against nature, and to gain their livelihood through associated