The document discusses several sources of Catholic Christian ethics including scripture, natural law, tradition, and experience. It notes limitations of each source and how they relate to and inform one another. It then examines Pope Paul VI's 1968 encyclical Humanae Vitae, which addresses artificial contraception. Key points of the encyclical are outlined, such as its view that procreation is not the only purpose of sex and distinction between natural family planning and artificial contraception.