In the human, as we have seen, the essential feature that makes for a labor capacity superior to that of the animal is the combination of execution with a conception of the thing to be done.  But as human labor becomes a social rather than an individual phenomenon, it is possible--unlike in the instance of animals where the motive force, instinct, is inseparable from action--to divorce conception from execution.  This dehumanization of the labor process, in which workers are reduced almost to the level of labor in its animal form, while purposeless and unthinkable in the case of the self-organized and self-motivated social labor of a community of producers, becomes crucial for the management of purchased labor.  For if the workers’ execution is guided by their own conception, it is not possible, as we have seen, to enforce upon them either the methodological efficiency or the working pace desired by capital.  The capitalist therefore learns from the start to take advantage of this aspect of human labor power, and to break the unity of the labor process (78).