This paper defends two related ideas: pure market and capitalist economies are different economic societies; neither can be adequately represented by theories of value but both can be accurately distinguished by a monetary approach. Within the framework of a simple modeling, we propose a conceptual clarification in four points. Firstly, market and capitalist economies are instituted by a principle of social quantification: money as the unit of account. Secondly, both economies are set in motion by a medium of circulation: money as the general equivalent. Thirdly, pure market society homogeneity is based on generalized access to money as the vehicle of autonomous expense (the carrier of unilateral action), while capitalist society heterogeneity is based on direct access to money reserved only to entrepreneurs and closed to monetarily dependent wage earners. Fourthly, if independent workers (integrated in a social division of labor) can be seen as motivated by the individual pursuit of utility, capitalists (engaged in an objective logic of capital accumulation) are driven by the subjective desire for money.