From Pope St. John Paul II’s encyclical Veritatis Splendor (1993):
All that has been said about theology in general can and must also be said for moral theology, seen in its specific nature as a scientific reflection on the Gospel as the gift and commandment of new life, a reflection on the life which “professes the truth in love” (cf. Eph 4:15) and on the Church’s life of holiness, in which there shines forth the truth about the good brought to its perfection. The Church’s Magisterium intervenes not only in the sphere of faith, but also, and inseparably so, in the sphere of morals. It has the task of “discerning, by means of judgments normative for the consciences of believers, those acts which in themselves conform to the demands of faith and foster their expression in life and those which, on the contrary, because intrinsically evil, are incompatible with such demands”.172 In proclaiming the commandments of God and the charity of Christ, the Church’s Magisterium also teaches the faithful specific particular precepts and requires that they consider them in conscience as morally binding. In addition, the Magisterium carries out an important work of vigilance, warning the faithful of the presence of possible errors, even merely implicit ones, when their consciences fail to acknowledge the correctness and the truth of the moral norms which the Magisterium teaches.
This is the point at which to consider the specific task of all those who by mandate of their legitimate Pastors teach moral theology in Seminaries and Faculties of Theology. They have the grave duty to instruct the faithful — especially future Pastors — about all those commandments and practical norms authoritatively declared by the Church.173 While recognizing the possible limitations of the human arguments employed by the Magisterium, moral theologians are called to develop a deeper understanding of the reasons underlying its teachings and to expound the validity and obligatory nature of the precepts it proposes, demonstrating their connection with one another and their relation with man’s ultimate end.174 Moral theologians are to set forth the Church’s teaching and to give, in the exercise of their ministry, the example of a loyal assent, both internal and external, to the Magisterium’s teaching in the areas of both dogma and morality.175 Working together in cooperation with the hierarchical Magisterium, theologians will be deeply concerned to clarify ever more fully the biblical foundations, the ethical significance and the anthropological concerns which underlie the moral doctrine and the vision of man set forth by the Church.
172 Congregation for the Doctrine of the Faith, Instruction on the Ecclesial Vocation of the Theologian Donum Veritatis (May 24, 1990), 16: Acta Apostolicæ Sedis [AAS] 82 (1990), 1557.
173 Cf. Code of Canon Law, Canons 252, 1; 659, 3.
174 Cf. First Vatican Ecumenical Council, Dogmatic Constitution on the Catholic Faith Dei Filius, Chap. 4: H. Denzinger-A. Schönmetzer, Enchiridion Symbolorum Definitionum et Declarationum de Rebus Fidei et Morum, 3016.
175 Cf. Paul VI, Encyclical Letter Humanæ Vitæ (July 25, 1968), 28: AAS 60 (1968), 501.
— Veritatis Splendor 110