218 THE SOCIAL THEORY OF GEORG SIMMEL For the purpose of this study Simmel’s Philosophy of Money is best suited to illustrate his conception of the function of a social metaphysics as distinct from the func- tion of a social science or a philosophic inquiry into the presuppositions of the social sciences. As metaphysics, it traces the relations of money to all the phenomena of social and cultural life and interprets modern civilization in terms of money as its functional category and symbol.