In this article, the author defends the idea that one of the positive results of modern economic analysis is the conviction that there is no natural law in economics. Thus, the most thorough scientific research which has tried to provide an analytical foundation for the mythical invisible hand, the "general equilibrium paradigm," has finally shown that such an equilibration process cannot be formally demonstrated. Hence, we can say that economists cannot demonstrate the existence of a law of "supply and demand" but, more simply, can assert that some causal but contingent relations may exist between price, supply and demand. According to this result, the critical approach of Kenneth John Arrow concludes with the necessity of social and moral rule (for the good functioning of the market). It is, thus, necessary to assume the contingent nature of economic rules, and the absence of natural law, and consequently, to modify economists' theoretical model.