Barter, Reason, Empiricism

Smith's "propensity to barter" is constituted by the concept of mutually beneficial exchange. Thus, it includes the rudiments of what is often characterized as 'enlightened self-interest'. Now, according to Kant, insofar as that concept entails that of an other as an end-in-itself, it is derived from Reason. Thus, an unaddressed methodological problem for Smith is the relation of Barter to Empiricism.