There are three major points to be considered on this feast of St. Thomas:
1) That we do for Enlightenment philosophy and all modern thought what St. T homas did for Aristotle and Plato. With consummate openness of mind, he principally engaged Aristotle's philosophy of being and transcended conceptual knowing with a new meaning of act, to wit, the act of esse. With this, he was able to engage Aristotle's rational assesment of the empirically real with a metaphysics of the transcendent supernatural. Aristotle's cosmos and philosophy of nature was assimilated into a universe created by a transcendent God whose very act was "Ipsum Esse." By the assimilation, Aristotle's original insights were not prejudiced but exalted.
2) The challenge today - for us - consists in assimilating the principal insights of modern thought, particularly the turn to the subject. This has been hitherto assessed as a negative turn in that it has been the occasion of negating the absolute value of the real and provoking the consequent "dictatorship of relativism" in all things moral. The apologist of the faith in recent memory has habitually found the exaltation of the subject to be the undermining factor with regard to absoluteness in morality.
The turn to the subject is an eminently positive turn in attitude in that it enhances realism rather than undermining it, and this because it is precisely the "I" is the prius of access to "being." Refer to the keynote address at the recent synod in Rome (October 8, 2008) when Benedict XVI made the breathtaking affirmation that the principal reality of all realities is the Word of God, and that Word is the Person of Jesus Christ who is the prototype of the human person. All reality has been created by and for Word of God. We access the the Word of God though the experience of the human person when he/she transcends self in the moral act - the first of which is the act of faith as response to the Word. One hears the Word (doesn't see it), takes it in and literally becomes it by living it. One becomes another Christ. In so doing, one experiences the esse of the self as absolute, in fact, absolute "good." Hence, our task is to do for our historical milieu what St. Thomas did for his.
3) And it would be good to do it with his principles, i.e. his valuation of esse as "act of all acts, perfection of all perfections" (S. Th. I-4-1 ad. 3). A perusal of John Paul II's "Fides et Ratio" #83 yields the affirmation that the human person is the locus of the encounter with the actu essendi and all metaphysical enquiry. The constitutive relationality of the act of all acts (esse) as the metaphysical account of the human person should be explored - now.
The conundrum of giving a realist and metaphysical response to the gay agendum of the present moment demands such a metaphysics of relation.
Recently, there has been a debate between Salzman/Lawler and Robbie George/Patrick Lee. Thumbnail sketch: S/L (catholics) oppose the Magisterial teaching on the immorality of gay acts proposing the very anthropology espoused by the Magisterium of Gaudium et Spes #24 that human persons are constitutively relational: "finding self... by the sincere gift of self." They have no metaphysical ground and offer that the "meaning" of the sexual encounter of homosexuals is defined by the loving attitude and intention that would be self gift in them.
George and Lee counter this by affirming that the body is ontologically constitutive of this interpersonal relationality and that there must be an organic, bodily complementarity taking place for the two to be truly one. The oneness must be a metaphysical, organic, enfleshed and complementary, "one."
Salzman/Lawler accuse George/Lee of deploying a reductionist metaphysic (which they do, since the underpinnings of their argumentation is being as "substance"). However, Salzman Lawler use a properly trinitarian derived anthropology, but without a metaphysic
To this, I offer the absolute need of a metaphysic to account for the absolute realism of relationality (and leave it to the purely subjectivistic and sentimental that created the "real" by sentimental whim) with a metaphysic that would not reduce and box the real within the category of substantial "in-itselfness."
St. Thomas of the 21st century, where are you? Who will understand John Paul II and Benedict XVI and explicitate a comprehensive metaphysics of the human person. Benedict XVI us calling for it in Chapters V and VI of "Caritas in Veritate."