The Article is organized as follows. Part I discusses the doctrinal writings of the Catholic Church as they relate to the moral obligations of public actors. As will be seen, these writings lend themselves to an interpretation that suggests a strong role for Catholic moral teaching in all aspects of public life. Part II examines the circumstances in which these writings may be applicable to the decision-making processes of the Supreme Court. Cases involving fundamental rights and liberties are given particular attention in this Section-for these are cases about which Catholic doctrine often has the most to say, and in which the potential for judicial lawmaking is often made most clear. This Section demonstrates that an activist theory of constitutional interpretation can find ample support in Catholic teaching. Part III considers the implications of the activist Catholic theory for judicial nominations, with the goal of emphasizing the potential relevance of religious doctrine in the confirmation process. The Article concludes with some observations about the potential limits of Catholic self-identification as a predictor of judicial behavior and the need for further empirical research to measure the actual impact of Catholic teaching on the judiciary.