Sympathy and the impartial spectator are, for Smith, perhaps the two most important notions to understand if one wishes to understand what gives rise to our moral judgments. Sympathy, or a correspondence between the sentiments of an actor and a spectator, is what one senses or is aware of that prompts a favorable judgment. It is the impartial spectator, however, whose sentiments and judgments correct those of the interested actor and spectator. Indeed, the judgments of the impartial spectator in time assume the role of the ultimate standards of moral judgment, not only for the individual but also for the community at large. The other two main elements of Smith's theory are his explanation of the human phenomenon known as conscience and his conception of human nature. In explaining what the human conscience is and how it develops, Smith puts the rest of his theory to work. Sympathy and the impartial spectator work in concert to create our conscience, and the process of conscience-formation, as well as the natural attraction to sympathy and the impetus to employ the impartial spectator procedure, are all motivated by principles and desires innate in human nature.

In this chapter, I begin by looking at Smith's conception of the human conscience, detailing what it is, how it develops, how it functions, and what role it plays in Smith's moral theory. Then I examine the principal elements of Smith's conception of human nature, which undergirds his entire moral theory.