Christ’s Role in Sacra Doctrina in Thomas Aquinas

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By Georgina DePugh, University of Dallas

An approach to Sacra Doctrina through Thomas Aquinas should flow from humble docility. According to Thomas, Sacra Doctrina is God’s knowledge of himself shared with the blessed in heaven and on earth.[1] Expressed in the Summa Theologica, Christ’s role in Sacra Doctrina is nothing other than the divine transmission of God himself shared through the incarnational principle.

An initial overview of all in theology is either addressing God (His nature) or addressing things as “coming from or going to God.”[2] Through Sacra Doctrina, theology has foundation which reveals both God and things in relation to God. The role of Christ in Sacra Doctrina is further necessary in understanding Thomas’ designation of theology with a divine wisdom. Before the consideration of theology as such, Thomas admits to the consensus that philosophy is the summit of intellectual endeavors. Thomas says if this is the case, then theology is of the divine sort–which is higher than that of temporal pursuit. He also says that in the practical sense, Sacra Doctrina is of a nobler science in that the practical form of the science is “eternal bliss.”[3] Yet Thomas states in his concern for knowledge, man has no knowledge directly about God insofar as His essence and nature are concerned. How does Sacra Doctrina as defined by Thomas allow man to get around this seemingly insurmountable obstacle between God the Creator and man the creature? Thomas explains the knowledge man can have of God which pertains to that of naturality. Humanity can have natural knowledge of God under the ratio of cause of effects—God qua cause.[4] It follows that revelation can give man some knowledge of God directly—of the Trinity. Man’s knowledge therefore from revelation is an effect of grace. This exposition of theology is a necessary foundation in understanding Christ’s role in Sacra Doctrina for Thomas most expressly shown the 12th and 13th questions of the Summa.

Before one can name God, Thomas precedes question 12 with an explanation of the ways in which man can know God. Thomas gives three ways one can know God. The first mode of knowing is through affirmation, “we see his causes as the unmoved mover.”[5] Secondly, man can know God by negation, “we see what God is not.”[6] Thirdly, “we see the good and glory in causes” whereby man can know God though excellence. After this foundation, it follows that man names as he knows. Hence, a name for God says more about what he is not. Interestingly, man names each thing known to him by highlighting some aspect of it common to other things. A name therefore designates a referent by way of a concept, and man names an object by his intellect. Following 12, Question 13 further addresses how we can name God substantially. This type of name signifies divine substance, but it falls short of a full representation.[7] Further, some names are causal which pre-exist in God, and some are negative that express the distance between creatures and God. Nevertheless, one can know all perfection exists in God. This specific notion, made confident to in Christ, re-directs the distortion in faith, and that of Moses Maimonides which holds that man cannot name God properly. The incarnation allows the whole definition to be applicable to the object—how we can name God properly. Hence, God is good—His goodness first is not contingent on one’s understanding and second penetrates man’s knowledge through the incarnation of Christ. Thomas regards metaphors as being said properly sometimes, but only of the ones that do not signify perfections.[8] Christ is the tangible perfection of any insufficient metaphor that which seeks to explain God in any intelligible way. For Thomas, words that signify pure perfections have no limit in God. Overall, to name God analogously, the name must be properly proportional applied to God proportionally.

Thomas designates a name specified properly proportional to God: One. This name therefore proposes God is one and further the experience of Christ is not a lesser ability. The son is therefore homoousia with God. Christ’s role in Sacra Doctrine reveals not only the relation of Creator to creature, but also the divine relations that seeks intimacy to be reflected among creatures. The nature of Christ, through the incarnation, as having been divinely communicated with the blessed in heaven and earth first shows that Jesus is divine, which means that he is in the same metaphysical place as God. Man can therefore know the language of the letter to the Philippians is nothing but literal when God “empties himself taking the form of a slave.”[9] For only through this divine communication, man can say there’s salvation for him. The Pelagian disfigurement of soteriology drags one away from the Christ that gives man the participation in divine life. Christ’s role in Sacra Doctrina, therefore reveals that salvation must come from outside, as if God is breaking in from the outside of one’s hard-shelled heart. Sacra Doctrina, through Christ, is an encounter with Who is absolutely other. This God is absolute other; hence man’s future can only be one, and in the finite of God, Jesus of Nazareth is given to humanity.

The tertia pars treats the grace of Christ, as He is the Head of the Church. The question of the Summa largely considers Christ’s reception of divinizing grace into his humanity and man’s share in that divinizing grace. This humanity is so united to the Son, that it truly is the human nature of the Son thus this humanity receives divinizing grace. Thomas therefore considers capital grace of Christ—the grace that man receives, which allows him to participate in the divine nature, comes from the divinizing grace of Christ.[10] Sacra Doctrina, as a communication of God’s knowledge transmitted through Christ encompasses both a capital grace and the threefold image of God in man according to Thomas. First, the natural aptitude for understanding and loving God is made fulfilled by the divinizing grace of Christ. All people by nature actively and habitually know and love God imperfectly. It is through the conformity to grace that man may know and love God perfectly. Hence, Sacra Doctrina is shared through Christ with the blessed in both heaven and earth—and the saints by likeness of glory. The intellectual substance shares a likeness of God. Understanding God is therefore in an inferior way, man needs to understand the Lord through a reception of Sacra Doctrina—the more perfect way. Thomas’s underlying Aristotelian philosophy says a human person is a rational animal, which sets him apart by thinking, considering, and understanding. These three things, significant to Thomas, are perfected in man’s nature particularly as happiness.[11] As perfection involves an operation of the intellect, the transmission of Scripture is a necessary aid to man understanding the highest perfection. God is the “highest intelligible,” therefore to know God is the last end in the intellectual substance.[12] Hence, what makes humans happy would simply be the ability to understand as much as possible—made possible through Sacra Doctrina. Thomas reminds man, “all things have God as their end.”[13] Man is at the base in the hierarchy of rational minds yet remains higher than the irrational. Human end must be to understand God to one’s own capacity.      Thomas says, “it is better to know God minutely than nuclear physics infinitely.”[14] What does it mean to understand God? The answer to this question is most perfectly expressed through Christ’s role in Sacra Doctrina for Thomas. A general knowledge of God is demonstrative[15] and requires a knowledge of faith. In a human being, this is the kind of knowledge that is perfective of their intellect. Sacra Doctrina is that which corrects one’s knowledge of God that is incorrect as it cannot be perfected, but only through the role of Christ presented in Philippians.[16] Man, unable to know everything in whole, requires the role Christ offers through his mission as a development of demonstrative knowledge. For Thomas this knowledge is what all humans want because one can only see the true God from a distance.[17] This is why Thomas’ treatment for the name of God as “Person” is significant, as Thomas writes:

Person signifies what is most perfect in all nature –that is, a subsistent individual of a rational nature. Hence, since everything that is perfect must be attributed to God, forasmuch as his essence contains every perfection, this name person is fittingly applied to God; not, however, as it is applied to creatures, but in a more excellent way.[18]

Both the kind of knowledge that is perfective of man’s intellect and names of God offer a complete understanding of Christ’s role in Sacra Doctrina. Christ’s personhood is the most excellent transmission of God’s knowledge, especially in a soteriological way. Man’s encounter with Christ, or the Christian experience, is one with God as He is in Christ. Jesus Christ is divine, and equally the name and person of Jesus is with the Father. Man looks up to God as He is one and the Father. One therefore experiences in Christ man’s immediate proximity to God. It follows that salvation, as one recalls the passion of Christ, is participation in divine life and in the incarnation. Jesus is metaphysically the communio of man and God. Christ is therefore the end, and He is what He manifests.

The divine transmission of God’s knowledge of himself shared through the incarnate Word ultimately gives the personal encounter with Christ that allows man to grow. For Thomas, all men are naturally attracted to goodness and a desire for happiness. God gave man the commandments, a work of wisdom inscribed in the natural order, because He created an order for goodness. The human being is made in God’s likeness and image; therefore, he is raised to a higher dignity through Christ’s role in Sacra Doctrina.


[1] ST.I.1.1.

[2] ST.I.1.7.

[3] ST.I.1.4.

[4] ST.I.2.3.

[5] Ibid.

[6] ST.I.13.5.

[7] Ibid.

[8] ST.I.1.9.

[9] Philippians 2:7, NABRE. 

[10] ST.8.5.

[11] ST.II-II.3.

[12] ST.12.A

[13] ST.I.1.1.

[14] Dr. Malloy, University of Dallas. Lecture ’19.

[15] ST.13.5.

[16] Philippians 2:7. NABRE.

[17] ST.13.5.

[18] ST.13.9.

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