From Pope St. John Paul II’s encyclical Fides et Ratio (1984):
The interpretation of sources is a vital task for theology; but another still more delicate and demanding task is the understanding of revealed truth, or the articulation of the intellectus fidei. The intellectus fidei, as I have noted, demands the contribution of a philosophy of being which first of all would enable dogmatic theology to perform its functions appropriately. The dogmatic pragmatism of the early years of this century, which viewed the truths of faith as nothing more than rules of conduct, has already been refuted and rejected;114 but the temptation always remains of understanding these truths in purely functional terms. This leads only to an approach which is inadequate, reductive and superficial at the level of speculation. A Christology, for example, which proceeded solely “from below”, as is said nowadays, or an ecclesiology developed solely on the model of civil society, would be hard pressed to avoid the danger of such reductionism.
If the intellectus fidei wishes to integrate all the wealth of the theological tradition, it must turn to the philosophy of being, which should be able to propose anew the problem of being—and this in harmony with the demands and insights of the entire philosophical tradition, including philosophy of more recent times, without lapsing into sterile repetition of antiquated formulas. Set within the Christian metaphysical tradition, the philosophy of being is a dynamic philosophy which views reality in its ontological, causal and communicative structures. It is strong and enduring because it is based upon the very act of being itself, which allows a full and comprehensive openness to reality as a whole, surpassing every limit in order to reach the One who brings all things to fulfilment.115 In theology, which draws its principles from Revelation as a new source of knowledge, this perspective is confirmed by the intimate relationship which exists between faith and metaphysical reasoning.
114 Cf. Congregation of the Holy Office, Decree Lamentabili (3 July 1907), 26: Acta Apostolicæ Sedis 40 (1907), 473.
115 Cf. John Paul II, Address to the Pontifical Athenaeum “Angelicum” (17 November 1979), 6: Insegnamenti, II, 2 (1979), 1183-1185.
— Fides et Ratio 97