The nature of perfect happiness, for St.Thomas Aquinas, reflects how grace perfects the nature of the intellect. Considering human nature, Thomas asserts that the question the human asks is quid est? (what is it?) and a curious human is not perfectly happy. Therefore, God, who graces the nature of the human intellect, satisfies the intellect’s greatest desire and allows the beatified to behold his very being. Humanity’s perfect happiness is the vision of God’s essence:
“Final and perfect happiness cannot consist in anything other than the vision of the divine essence. God himself as humanity’s ultimate end or perfect happiness far exceeds the means within human nature, thus the necessity of grace. The perfection of a rational creature consists not only in what belongs to it according to its nature, but also in what is attributed to it on account of a supernatural sharing in divine goodness.
God has chosen to give grace to humans so that they can “do and wish supernatural good” or “carry out works of supernatural virtue, which are meritorious. As God has made human beings capable of doing and wishing (free will), God allows human agency in beatification. In other words, grace does not purify humans without regard to human nature; “grace does not destroy nature but perfects it.
Thomas says that a person turns to God by his free will, which means that humans, naturally endowed with free will, turn to God in accordance with their nature.
It is, however, not that simple. As Thomas addresses the need for grace, he argues that sin has weakened human free will and that “free will cannot be turned to God unless God himself turns it.
St. Thomas asserts that a human can be turned to God by grace with free movement of the will. There is no contradiction here, because “God’s will universally causes being and every consequence of being, and so both necessity and contingency. Thus, there is no category of action outside of God, who is the First Mover, and divine and human action are not in a competitive relationship.
Thomas offers an example:
This is like the way in which the spirit of a soldier is bent toward seeking victory by the motion of the leader of the army, and toward following the regimental flag by the motion of the flag bearer. And thus since God is, absolutely speaking, the first mover, it is by his motion of directing everything in the general tendency toward goodness that everything seeks to be made like God in its own way.”
Thomas also maintains that grace affirms the human intellect as it brings the human to beatitude. Humans cannot know or desire their supernatural end without grace revealing that end. Since God’s will is not to save a clueless being, God reveals to humans “truths that exceed human reason” so they may “direct their thoughts and actions” to their supernatural end.13 Though the revealed truths exceed human reason, they are still in accordance with the intellect because grace gives the intellect what is proper to the intellect—knowledge.
Thus, grace touches the intellect according to its nature, not overriding or demolishing it, giving it “a more perfect knowledge of God.” Moreover, God does not dump into the intellect all the revealed truths at once. God designed the human intellect to develop by building truth upon truth, and out of his great care for humans as he created them God actually teaches the truths to humans. The human being, taught by God, learns of perfect happiness “little by little, according to the ways of human.
Having argued that grace accommodates the human will and intellect, we turn to the way grace is given through the sacraments to humans as embodied beings.
Thomas declares that God gives humans grace through the sacraments precisely because God affirms the material nature of the humans he created. At this point it should not surprise us that Thomas writes, concerning the sacraments, “It is characteristic of divine providence to provide for each thing according to the requirements of its condition. So God, in his wisdom, gave humans the sacraments—“bodily and perceptible signs” that cause grace “in a way consistent with [human] nature. God meets humans where they are because of what they are: embodied beings. God offers to humans a way of receiving grace in precisely the arena—the material world—which captures the attention of embodied beings.
In his articulation of the transubstantiation of the Eucharist (Christ’s real presence in the Eucharist), Thomas fleshes-out the way in which grace accommodates human embodiment by way of the sacraments.
Thomas explains that Christ loves us enough to be friends with us, and furthermore “it is the special feature of friendship to live together with friends. He continues: “[Christ] promises us his bodily presence as reward…yet meanwhile in our pilgrimage he does not deprive us of his bodily presence, but unites us with himself in this sacrament through the truth of his body and blood.
Having already established in his general discussion of the sacraments that in the Eucharist there is something material which causes grace, Thomas here states that the bread and the wine become the actual, physical body and blood of Christ. Surpassing the degree to which the other sacraments offer grace in the material, the Eucharist contains the very body of the giver of grace himself. With reference to friendship which requires bodily presence, God gives grace by honoring the nature of the human as embodied and physically offering himself as friend in the elements. He refers to the Eucharist as “the sign of supreme charity.
Thomas Aquinas claims that humans in the state of sin need grace to achieve perfect happiness for two reasons: to heal their corruption in order to be able to achieve natural good and to elevate them to be able to act proportionately with their supernatural good, which is the vision of God. Because grace works to eliminate human sin and bring the human to an end which surpasses his natural capacity, Thomas argues that grace does not destroy the human—a being with a free will, intellect, and body. He demonstrates that grace allows for the free movement of the will toward God and gives the intellect what it seeks—the knowledge of God.
He shows that God regards human embodiment and accordingly offers grace in the sacraments, which are material and visible and thus accessible to humans. He makes a particularly poignant defense of his claim that grace functions according to human nature in his doctrine of the Eucharist—that Christ’s body is physically present in the bread and the wine. The Eucharist causes grace in embodied beings by becoming the actual body of the giver of grace; grace especially functions in this sacrament according to human nature in that the grace giver, who has called us friends, becomes physically present according to the standards of friendship between embodied beings.
Therefore, grace need not eliminate the human in the perfection process, for that would not result in perfect happiness at all. By describing the way grace accommodates the human will, intellect, and body, Thomas proclaims that it is indeed the human qua human—the human according to his created nature-that is brought to perfect happiness, which is the very vision of God.