Forbonnais’s and Graslin’s Attempted Explanations of ‘the Diamond-Water Paradox’ before Adam Smith

This paper discusses F. V. D. de Forbonnais’s and J.-J.-L. Graslin’s value theories and examines their explanations of ‘the diamond-water paradox’. They criticized the physiocrat’s conceptual distinction between ‘productiveness’ and ‘sterility’ and discussed each theory of value. Forbonnais explained ‘the diamond-water paradox’ according to the assumption that ‘the natural order’ normally governed value of different goods based on essential utility for our existence. The capriciousness of the rich tends to weaken the function of the natural order. This behaviour is the cause of the high value of diamonds independently from the essential utility. Thus, Forbonnais emphasized the natural order and utility; nevertheless, Graslin’s explanation of the paradox was founded on the concepts of need, utility and scarcity from a subjective point of view, which has clear links to the marginalist revolution in the 1870s. Graslin provided a detailed explanation of the interaction between utility and scarcity, before Adam Smith’s distinction between what is called ‘value in use’ and ‘value in exchange’.