Aquinas’ second argument in favor of Scotus’ position, and his response to the contrary:
Objection 2. Further, it belongs to the omnipotence of the Divine power to perfect His works, and to manifest Himself by some infinite effect. But no mere creature can be called an infinite effect, since it is finite of its very essence. Now, seemingly, in the work of Incarnation alone is an infinite effect of the Divine power manifested in a special manner by which power things infinitely distant are united, inasmuch as it has been brought about that man is God. And in this work especially the universe would seem to be perfected, inasmuch as the last creature–viz. man–is united to the first principle–viz. God. Therefore, even if man had not sinned, God would have become incarnate.
Reply to Objection 2. The infinity of Divine power is shown in the mode of production of things from nothing. Again, it suffices for the perfection of the universe that the creature be ordained in a natural manner to God as to an end. But that a creature should be united to God in person exceeds the limits of the perfection of nature.
Here the Angelic Doctor is basically denying that the perfection of man, namely, his union with God the first principle, would have been accomplished through Christ the Mediator if there were no need for the Redemption. As a result, he is distinguishing two economies of grace: one in Christ, gratia Christi, and one apart from Christ, gratia Dei. Adam and Eve before the fall would have fallen into the category of the gratia Dei, which, in the thomistic scheme, would be the category of the Angels to this day. So before the fall, Adam and Eve were not under the headship of Christ, but were receiving grace directly from God. After the fall, thanks to the merciful Redemption, they and all of their progeny now fall under the headship of Jesus, the gratia Christi. This would mean that the Angels always remain under the gratia Dei, since they never need a Redemption; thus the headship of Christ over them would be “accidental” whereas His headship over us would be as a result of sin.
For the Subtle Doctor and the Franciscan school there is only one economy of grace for men and Angels, the gratia Christi. All of the Angels and all men, including Adam and Eve before the fall, are always under the headship of Christ. This syncs up with the Pauline passages where the Angels are under Christ’s headship (cfr. Col 1:15-18; Eph 1:10, 21-23; 3:8-11; Heb 1; etc.)
There are some who maintain the primacy of Christ and an Incarnation because of man’s need for a Mediator (sin or no sin). In this case the primary motive of the Incarnation would be man’s deification, or divinization, or theosis in Christ (in Catholic theology these terms are valid, provided we maintain that man “participates in the divine nature” 2 Pt 1:4 while remaining a creature – no pantheism allowed! God is God, and we are not). They approach the Incarnation in this fashion: if Adam had not sinned, Christ would have come to elevate man to a participation of the divine, trinitarian life. In this case, Christ is the Mediator of divine grace regardless of any consideration of sin and thus all men and Angels would fall under the headship of Christ. Here we speak of one economy of grace, gratia Christi, for all of the elect. This motive for the Incarnation finds many confirmations in the prayers of the Mass which express the universal mediation of Christ (sin or no sin), i.e. “By the mystery of this water and wine may we come to share in the divinity of Christ who humbled Himself to share in our humanity”; and “Through Him and with Him and in Him, to You, O God, Almighty Father, in the unity of the Holy Spirit, is all honor and glory forever and ever. Amen.” With the absolute primacy of Christ these prayers express a single economy of grace: the gratia Christi, and would be true even if there were no original sin.
However, and this may come as a shock even to those who are acquainted with the Franciscan thesis, the Subtle Doctor even denies this latter explanation as the primary motive of the Incarnation. For him the Incarnation is not occasioned by anything created (neither man’s need for Redemption nor his need for the grace of divine sonship), but is willed by God first and absolutely without any consideration of other creatures – Christ is willed and predestined first, and this to receive the maximum grace and glory from God in His Sacred Humanity and to offer perfect latria, that is, to give the maximum glory to God ad extra. This is the perfect communication of divine love outside of the Godhead and this was the centerpiece of God’s plan, then everything else is willed in Christ and for Christ. First, the Humanity of Christ is predestined to the maximum grace and glory through the hypostatic union, then everyone else is predestined in Christ. More on this later (or look up the section on Scotus). This is, by the way, what St. Francis de Sales taught (see this link: St. Francis de Sales, the Providence of God, & the Primary Motive of the Incarnation).
Obviously, it goes without saying that there is no “first” and “second” and “third” and “then” in God who is outside of time. This is true indeed; however, there is priority in God’s plan and we simply have to use human terms to communicate this, terms like “first”, “before”, “then”, “after”. While St. Thomas Aquinas and Bl. John Duns Scotus both speak of a priority in the divine decree of creation, they are also both fully aware that God did not “think out” His plan of creation in successive moments because God is above time, not in it; God created time as opposed to we who were created in time. Both Doctors are agreed that God willed in an orderly fashion without succession of moments; however, they disagree about what that orderly fashion is.
Fr. Maximilian M. Dean