Five questions regarding the nature of the moral sense, the origin of conscience, the development of morality, variability in the moral sense, and the relation of morality to behavior are examined from the point of view of four theoretical approaches (psychoanalytic theory, social learning theory, cognitive-developmental theory, and evolutionary psychology). In addition, some concepts and findings from outside the four approaches are also touched upon. The moral sense is shown to be complex, comprising cognitions, feelings, and behaviors. The theoretical approaches disagree regarding the issues of whether conscience directly reflects social teaching, or is constructed by the developing individual. They also disagree on whether moral development is incremental or stagewise. Explanations of individual, gender, and cultural differences in morality differ across the four approaches. None of the approaches explains the relation of behavior to morality; rather, application of social psychological theories is suggested.