top of page

St. Thomas Aquinas' "Cur Deus Homo?"

If you would like to help support my ministry and get access to a bunch of awesome benefits, become a Patron or join SubscribeStar

If you want daily notes/summaries of St. Thomas' works, sign up for the Annotated Thomist.

If you need more personalized help reading the Summa, I am available for 1-on-1 sessions, here.

St. Thomas writes, “Our Lord has taught us that this beatific knowledge has to do with two truths: namely, the divinity of the Trinity and the humanity of Christ.” (CT.BookI.C2.2)

The incarnation of Our Lord Jesus Christ can be said to be the most central truth of the faith, for the incarnation reveals the Trinity, “if you have seen Me, you have seen the Father.”

Further, the incarnation is the instrument of our salvation, the foundation of our hope. Lastly, the incarnation is the supreme expression of love, stirring us to love God and neighbor.

This incarnation, along with so many illustrious effects, is also the most fitting mode of our salvation as can be seen from the light of reason (although not providing a demonstrative proof of such, as was laid out in yesterday’s article).

When any workman builds a certain thing, he does it through the conception that is present in his mind. When a builder builds a house, he has a certain image of that house in his mind that he conforms the house to. Now, the Son of God is the word that proceeds from the Father by way of intellection. Therefore, the world was created through the Son of God as a builder builds through his mental word. (c.f., DeRatio.C5.3)

Now, let’s say there is a storm wherein the house is damaged. How would the builder repair the house? The builder would repair the house after that same mental form which he created it with. Therefore, so also will the redemption of what is destroyed by sin occur by the word of God.

It is clear that rational creatures are of greater intrinsic value than other creatures. For, all other creatures are ordered to our good, and we rule over all. This is reasonable, for rational creatures have control over their faculties and are not bound and compelled by a necessity of nature. Yet, irrational creatures are not free. It is a universal law that what is not free serves what is free. Therefore, it is most fitting that God redeems rational creatures more than if the entirety of irrational creation was destroyed. (c.f., DeRatio.C5.4)

Now, there are two types of rational creatures: the angelic and human. The angelic is purely intellectual, whereas the human is both intellectual and bodily. Both have freedom; therefore, both can fall. Now, the will is ordered towards loving the good. Therefore, a fall in these creatures would consist of a certain disorder to a lesser good, i.e., sin. (c.f., DeRatio.C5.5)

Now, an intellectual nature is immutable in itself, for it is only by a union with what is corporeal that the intellectual becomes changeable in itself. Now, the angels are pure spirits; therefore, “the immutability of their nature makes them impenitent from any direction they once take.”

Yet, man is joined with a body. Therefore, while man is in his earthly body, he does have a certain opportunity for penance. For, his nature is mutable. But, hereafter, while separated from his body (before the resurrection of the dead), there is no hope of repentance.

Therefore, it was fitting that God’s Word should not save the irrational creatures but rational, and not the angelic, but human. (c.f., DeRatio.C5.6)

The way of restoration by God’s Word should correspond to two things; first, the nature being restored, and, second, the nature of the sickness. The nature of that to be restored, as laid out above, is the will of man. Therefore, the restoration should involve the will. The nature of the sickness is a perversity of will; therefore, the will should be called back to righteousness. Now, the will’s principle ordering is towards the good, which we call love. Further, God is the supreme good, goodness itself. Therefore, the righteous ordering of the will is to love God above all created and mutable goods. (c.f., DeRatio.C5.7)

To excite our love towards God, there was no better way than that God should become man. Love is to desire the good of another. Now, love is expressed more strongly when a greater hardship is wrought for the beloved. Thus, the love of a husband for his wife and the wife for her husband is more readily shown in sickness than in health. Therefore, the words of our Lord are confirmed that “greater love hath no man than this, that a man lay down his life for his friends.” Therefore, to most supremely show His life towards us, God was to die. Yet, God in Himself cannot die according to his nature, for, he is supremely immortal. Therefore, God was to join to Himself a mortal nature. This excites love most eminently in man, for “nothing can provoke love more than to know that one is loved.” (c.f., DeRatio.C5.8)

Further, we love things more the more they are known. For, the intellect presents a certain thing under the aspect of good to the will to love. Yet, if the intellect does not grasp the thing, it cannot present it to the will to love. So there is great difficulty in grasping the Divinity by the littleness of our minds. Therefore, God willed to become man that even little children may readily know and love God. (c.f., DeRatio.C5.9)

Further, we are spurred to hope for a future good when that good is clearly presented before us. For, if promised some great good, greater than even the angels are capable of, we would hardly hope in it unless clearly presented to us. Now, there is no greater way that God could present his willing to be closely united to us than by uniting himself hypostatically to our nature. (c.f., DeRatio.C5.10)

Lastly, it spurs us from subjecting ourselves again to unrighteousness. For, “if man has such a great dignity by God’s judgment and he is so close to him that God wanted to become man, it is unworthy of man to subject himself improperly to things inferior to God.” (DeRatio.C5.11)

102 views0 comments


bottom of page