When Freud introduced into psychoanalytic theory his threefold division of the mind, he made the study of moral development fundamental to that theory. Several of the important works he subsequently produced also contain discussions of this topic. This paper concerns primarily the discussion found in Civilization and Its Discontents. In section 1, I consider how in this work the explanation Freud gave of the way a child acquires a conscience deviates from explanations he gave in earlier works, and I argue that the explanation represents a major change in his theory, one that yields a more cogent account of the child's acquisition of a conscience. In section 2, I consider difficulties in the conceptual scheme, as Freud described it, that undergirds his explanations, and I argue that these difficulties, particularly as they pertain to the relation between the concepts of superego, conscience, and a sense of guilt, can be resolved in a way that saves the explanation from an incoherence that Freud's own resolution, presented in Civilization and Its Discontents, entails.