This chapter explores how communication permeates his consideration of the exchange of goods and morality. It argues that Smith’s science of moral philosophy elucidates his grappling with extant misunderstanding of the nature of one’s interactions with external things. The chapter examines how, inspired by Smith’s method of the correction, he then similarly used communication to elucidate the mechanism of the correction of misunderstanding real prices and others’ inner sentiments. It describes Smith’s moral philosophy as the science of commerce as communication, considering the contextual and textual reasons that he chose the effect of communication as his topic and task. The chapter discusses the meaning of commerce and shows that Smith considered commerce to be almost interchangeable with communication in Wealth of Nations. It also examines how his theory of perception is the foundation of his theory of interpersonal communication in The Theory of Moral Sentiments.