Gregg Allison explains the Roman Catholic axiom of Grace-Nature by saying that “nature is capable of receiving and transmitting the grace of God. So think of water, bread, and wine. Those are elements within nature. Water is capable of receiving the grace of God when it’s consecrated by a bishop and communicating that grace of God when a priest sprinkles water on the head of an infant. And that infant then is infused with the grace of God cleansing the infant from original sin, regenerating the infant, incorporating the infant into the Catholic Church. So nature — in this case, water — becomes a vehicle for the grace of God. Bread and wine, when consecrated by the priest, become the body and blood of Jesus Christ and thereby when the Catholic faithful take those elements, they’re receiving the grace of God through these natural elements.”
Further in his book Allison draws out the implications of one of the two main axioms of Catholic Theology: the Grace-Nature continuum:
The words of Scripture – or, more specifically, the things to which the words of Scripture point (realm of nature) – contain hidden meanings and are capable of communicating those deeper meanings as divine truths (realm of grace).
Doctrine of Humanity
The Catholic system is characterized by a “moderate optimism regarding man’s ability (realm of nature) to be stirred by grace and to cooperate with its elevating process.” Moreover, considering his ontological receptivity for grace, man is viewed as an intrinsically religious being in whom grace is experienced as part of man’s own self. One manifestation of this characteristic is Adam and Eve’s reason (in their original created state) exercising a controlling influence over their feelings/passions ad bodily desires.
Doctrine of Sin
Catholic theology believes that, with the introduction of sin, this original structure of human nature was disrupted, with the lower aspects of Adam and Eve’s nature usurping the role of reason. Yet the Catholic system does not believe that sin’s impact was so devastating that human nature lost its capacity for grace.
Doctrine of Salvation
Catholic theology views the process by which God rescues fallen human beings as synergistic, that is, a cooperative venture between divine grace and human effort (the realm of nature), aided by grace, to work as to merit eternal life. Moreover, it considers the operation of salvation to be infused of divine grace into people, by which their nature is transformed. This point dovetails with Catholic theology’s understanding of the goal of salvation as deification, or the process by which human nature, through grace, becomes more and more like God. If this process is interrupted through engaging in mortal sin, it can be restarted through the sacrament of Penance by which grace is conveyed again for the perfection of human nature. Finally, if this process is not completed in this earthly lifetime, that is, if grace has not fully elevated human nature to perfection before death, existence after death in purgatory promises to finish the purification procedure.
Catholicism maintains that created elements in nature – for example, water, oil, bread, and wine – are capable of transmitting divine grace as the sacraments of Baptism, Confirmation, and the Eucharist are administered. Moreover, these elements (realm of nature), when consecrated (realm of grace), are effective in conveying grace ex opere operato, that is, just by their administration as sacraments. Also, it views the Eucharist as conferring incorruptibility on the body and thus serving as a foretaste of the resurrection. Finally, Catholic theology understands the bread and the wine (realm of nature) to be offerings to God by the Church (realm of grace).
For the Catholic system, grace must be concretely expressed in nature, and the highest tangible expression of grace (after Jesus Christ himself) is the Catholic Church. This aspect is especially seen in the Church’s association of the forgiveness of sins with its priesthood. Indeed, by the sacrament of Holy Orders, men (realm of nature) are consecrated so as to be able to administer the sacraments (realm of grace).
The Catholic Church is characterized by hierarchy, specifically between the laity (on the low end) and the clergy (on the high end), with a hierarchical structure also existing among the clergy between deacons (on the lowest end), priests (in the middle), and bishops (on the highest end). A hierarchy is also generally in evidence between the faithful (on the low end), the religious (the middle), and the saints (the highest end).
Catholic theology believes that the four cardinal human virtues (realm of nature) – prudence, temperance, fortitude, justice – are understood, appreciated, and practiced by human beings apart from grace, which functions not to create but to purify and elevate these virtues. It also emphasizes that natural law – a law derived from the realm of human nature and known by human beings through reason, enabling them to know right from wrong – still functions despite human sinfulness, in a somewhat intact manner to guide human choices.
Doctrine of Mary
Mariology expresses the quintessential characteristics of the Roman Catholic nature-grace motif. Mary, as a fully human being, is in the realm of nature; however, due to her immaculate conception, her human nature is not fallen, and, through her cooperation with grace, it remained unfallen throughout her life. Accordingly, in Mary’s nature, grace found complete openness and full capacity for cooperation, leading to the incarnation of the Son of God and her meritorious sufferings at the foot of the cross.
– All from direct quotes of Allison, Roman Catholic Theology, pages 50-52. Copyright laws forbid reproducing over 10% of material. This post falls well within legality.