A central aim of Smith's The Theory of Moral Sentiments is to give an account of the process of making moral judgments that is grounded in empirical evidence. He wanted to make a study of human relations in the same way Newton made a study of heavenly bodies—by observing the phenomena and attempting to generate rules that describe their regular behavior. In this chapter I shall argue that an examination of Smith's analysis of human morality in TMS reveals that the rules he has found that describe our moral behavior conform to a determinate model, a model that Smith develops throughout the course of his book. This model is of a market in which free exchanges among participating people give rise, over time, to an unintended system of order. Specifically, Smith understands the nature of moral judgments, including their concomitant features of the impartial spectator procedure and the human conscience, to be the codified results, both at the social and the individual levels, of a coherent and orderly system of morality that is effected by individuals who did not intend to effect it. Put differently, this human institution has developed and is maintained by what I propose to call a “marketplace of morality.”

Now the mention of a market will conjure up in the contemporary mind only one thing—economics. In Smith's day, too, the term was primarily used to refer to arenas in which merchants exchanged their goods or in which consumers bought the goods of producers.