Martin Bieler writes,
“The encyclical Fides et Ratio is an impressive document of the Catholic Church’s esteem of philosophy (57ff.)
“Although it is the declared intention of Fides et Ratio not to canonize any particular philosophy (49,78) there can be no doubt about the fact that the encyclical moves along the lines of Thomas Aquinas’ metaphysics when it outlines the future tasks of philosophical investigation.
“First of all, it strongly emphasizes the importance of a philosophy of being (5, 66, 90, 97) which meets the necessary requirements of a metaphysics that is indispensable for unfolding the truth revealed in Christ (82-83).
“Second, it seems to conceive a philosophy of being in the way Aquinas does by referring to the ‘act of being’ (actus essendi): ‘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’ (97.)
Martin Bieler, “The Theological Importance of the Philosophy of Being” in Reason and the Reasons of Faith, edited by Paul J. Griffiths and Reinhard Hütter, T & T Clark International, New York, 2005, pp. 295-296.