From Pope St. John Paul II’s encyclical Fides et Ratio (1984):
The word of God is addressed to all people, in every age and in every part of the world; and the human being is by nature a philosopher. As a reflective and scientific elaboration of the understanding of God’s word in the light of faith, theology for its part must relate, in some of its procedures and in the performance of its specific tasks, to the philosophies which have been developed through the ages. I have no wish to direct theologians to particular methods, since that is not the competence of the Magisterium. I wish instead to recall some specific tasks of theology which, by the very nature of the revealed word, demand recourse to philosophical enquiry.
Theology is structured as an understanding of faith in the light of a twofold methodological principle: the auditus fidei and the intellectus fidei. With the first, theology makes its own the content of Revelation as this has been gradually expounded in Sacred Tradition, Sacred Scripture and the Church’s living Magisterium.88 With the second, theology seeks to respond through speculative enquiry to the specific demands of disciplined thought.
Philosophy contributes specifically to theology in preparing for a correct auditus fidei with its study of the structure of knowledge and personal communication, especially the various forms and functions of language. No less important is philosophy’s contribution to a more coherent understanding of Church Tradition, the pronouncements of the Magisterium and the teaching of the great masters of theology, who often adopt concepts and thought-forms drawn from a particular philosophical tradition. In this case, the theologian is summoned not only to explain the concepts and terms used by the Church in her thinking and the development of her teaching, but also to know in depth the philosophical systems which may have influenced those concepts and terms, in order to formulate correct and consistent interpretations of them.
88 Cf. Second Vatican Ecumenical Council, Dogmatic Constitution on Divine Revelation Dei Verbum, 10.
— Fides et Ratio 64-65