Catholic theology of sexuality, like Catholic theology in general, is drawn from natural law, canonical scripture, divine revelation, and sacred tradition, as interpreted authoritatively by the magisterium of the Catholic Church.Sexual morality evaluates sexual behavior according to standards laid out by Catholic moral theology, and often provides general principles by which Catholics are able to evaluate whether specific actions meet these standards. Much of the Church's detailed doctrines derive from the principle that "sexual pleasure is morally disordered when sought for itself, isolated from its procreative and unitive [between spouses] purposes".
The Catholic Church teaches that human life and human sexuality are inseparable. Because Catholics believe God created human beings in his own image and likeness and that he found everything he created to be "very good," the Catholic Church teaches that human body and sex must likewise be good. The Church considers the expression of love between husband and wife to be an elevated form of human activity, joining husband and wife in complete, mutual self-giving, and opening their relationship to new life. As Pope Paul VI wrote in Humanae vitae, “The sexual activity, in which husband and wife are intimately and chastely united with one another, through which human life is transmitted, is, as the recent Council recalled, ‘noble and worthy.’” In cases in which sexual expression is sought outside sacramental marriage, or in which the procreative function of sexual expression within marriage is deliberately frustrated (e.g., the use of artificial contraception), the Catholic Church expresses grave moral concern.