Thomas Aquinas Commentary Galatians 4:4-5

"but when the fulness of the time came, God sent forth his Son, born of a woman, born under the law, that he might redeem them that were under the law, that we might receive the adoption of sons." — Galatians 4:4-5 (ASV)

Here the Apostle applies to Christ the simile he has proposed.

He does two things:

1. First, he makes the application.
2. Second, he discloses the purpose of the reality that corresponds to the simile (verse 5).

It should be noted that in the simile proposed earlier, four items were pointed out in order. But now, in applying them to Christ, the Apostle begins with the last one: the setting of a time. The reason for this is that the time in which Christ was humiliated and the faithful were exalted is the same. Hence he says, But, when the fulness of the time was come, meaning, after the time set by God the Father for sending His Son had been accomplished. This is how the phrase is used in Luke 2:6: “Her days were accomplished, that she should be delivered.”

This time is called “full” for several reasons. It is full because of the fullness of the graces given in it, according to Psalm 64:10: “The river of God is filled with water; thou hast prepared their food: for so is its preparation.” It is also full because it is the fulfillment of the figures of the Old Law: “I am not come to destroy but to fulfill” (Matthew 5:17). And it is full because of the fulfillment of the promises: “And he shall confirm the covenant with many, in one week” (Daniel 9:27).

However, when Scripture says that the time concerning Christ was accomplished, as in the phrase, But, when the fulness of time was come, this should not be explained as a necessity imposed by fate. Rather, it should be understood as a divine ordinance, about which Psalm 118:91 states: “By thy ordinance the day goeth on; for all things serve thee.”

Two reasons are given for why that time was preordained for the coming of Christ. The first relates to His greatness; since He who was to come was great, it was fitting that people be prepared for His coming by many signs and preparations. As it is written, “God, who, at sundry times and in divers manners, spoke in times past to the fathers by the prophets, last of all in these days hath spoken to us by his Son” (Hebrews 1:1). The second reason relates to the role of the One who was coming. Since a physician was to come, it was fitting that before His arrival, people should be keenly aware of their infirmity—both regarding their lack of knowledge under the law of nature and their lack of virtue under the written Law. Therefore, it was fitting that both the law of nature and the written Law should precede the coming of Christ.

Second, he applies the simile regarding Christ’s dignity as heir when he says, God sent his Son. This refers to His own natural Son; and if a son, then also an heir. He says, his Son—that is, His own, natural, only-begotten Son, not an adopted one: “God so loved the world as to give his only begotten Son” (John 3:16).

God sent Him, I say, without the Son being separated from the Father. He was sent by assuming human nature, yet He remained in the bosom of the Father: “The only begotten Son, Who is in the bosom of the Father” eternally (John 1:18). And again, “And no man hath ascended into heaven, but he that descended from heaven, the Son of Man, who is in heaven” (John 3:13). Although He descended by assuming flesh, He is nevertheless in heaven. He was sent, not to be where He was not before, because even though He came to His own in the flesh, He was already in the world by the presence of His divinity, as is said in John 1:14. Furthermore, God did not send Him as a mere servant, because His mission was the assumption of flesh, not the setting aside of majesty.

Therefore, God sent His Son to heal the error of the desiring part of our nature and to illumine the ignorance of the rational part: “He sent his word and healed them: and delivered them from their destructions” (Psalms 106:20). He also sent Him to deliver them from the power of the devil, which preys on the weakness of the aggressive part of our nature: “He shall send them a Savior and defender to deliver them” (Isaiah 19:20). He was sent as a deliverer from the chains of eternal death: “I will deliver them out of the hand of death. I will redeem them from death: O death, I will be thy death” (Hosea 13:14). And He was sent to save them from their sins: “For God sent not his Son into the world to judge the world but that the world may be saved by him” (John 3:17).

Third, he applies the simile regarding Christ’s smallness when he says, made of a woman. As it is written, “For a child is born to us” (Isaiah 9:6), and, “He emptied himself taking the form of a servant” (Philippians 2:7). He made Himself small not by setting aside His greatness, but by taking on smallness.

In interpreting the phrase made of a woman, two errors must be avoided. The first is that of Photinus, who said that Christ was only a man and received the beginning of His existence from the Virgin—in other words, that Christ was “made of a woman” as though His existence began entirely from her. This is false because it contradicts what is said in Romans 1:3: “Who was made to him of the seed of David, according to the flesh.” The Apostle does not say “according to His person,” for His person, the hypostasis of the Son of God, exists from eternity.

An analogy may help. When a shield has just become white, it is not proper to say that the substance of the shield itself has just come into being, but that whiteness has been newly added to it. In the same way, from the fact that the Son of God newly assumed flesh, it is not proper to say that the person of Christ has just come into being, but that a human nature has been newly added to that eternal person. This is like certain things that affect a body without changing the body itself. Some things, like forms and absolute qualities, affect an object and change it, while other things affect it without changing it. The assumption of flesh is of this latter sort, as it signifies a relationship. Therefore, the person of the Word is in no way changed by it.

This is why, in divine matters, we use terms that signify a relationship in a temporal sense. For example, we say in Psalm 89:1, “Lord, thou hast been our refuge,” or we say that God became man. But we do not use terms signifying forms and absolute qualities in this way, so as to say that God was made good or wise, and so on.

The second error to avoid is that of Ebion, who said that Christ was born from the seed of Joseph. He was led to this by the phrase “born of a woman,” because according to him, the word “woman” always implies a loss of virginity. But this is wrong, for in Sacred Scripture, “woman” can also simply denote the female sex, as in Genesis 3:12: “Adam said: The woman who thou gavest me to be my companion gave me of the tree.” Here Adam calls her a woman while she was still a virgin.

Furthermore, the phrase made of a woman destroys two other errors. First is the error of Nestorius, who said that Christ did not take His body from the Virgin but from the heavens, and that He passed through the Blessed Virgin as through a corridor or channel. This is false, for if it were true, He would not have been, as the Apostle says, made of a woman. The preposition “of” [ex] denotes the material cause.

Likewise, this phrase refutes the Nestorian error that the Blessed Virgin is not the mother of the Son of God but only of a human son. This is shown to be false by the Apostle’s words here, that God sent His Son, made of a woman. Now, one who is made of a woman is her son. Therefore, if the Son of God was made of a woman—namely, the Blessed Virgin—it is clear that the Blessed Virgin is the Mother of the Son of God.

Moreover, although the Apostle could have said “born of a woman,” he distinctly says made, not “born.” To be “born” implies being produced from a principle conjoined to it (as fruit is born from a tree), while to be “made” can imply production from a principle separate from it (as a wooden chest is made by an artisan).

The principle of human generation is twofold. First is the material principle. In this regard, Christ proceeded from a conjoined principle, because He took the matter of His body from the Virgin. It is according to this that He is said to be born of her: “Of whom was born Jesus, who is called Christ” (Matthew 1:16). The other is the active principle. In Christ’s case, this principle (that is, the power that formed His body) was not conjoined but separate, for the power of the Holy Spirit formed it. In this respect, He is not said to have been “born” of a woman, but “made,” as if from an external principle. From this, it is also clear that the phrase “of a woman” does not imply a loss of virginity; otherwise, the Apostle would have said “born” and not “made.”

Fourth, he applies the simile regarding the aspect of subjection when he says, made under the law. A difficulty arises here from what is said later: “If you are led by the Spirit, you are not under the law” (Galatians 5:18). If Christ is not only spiritual but is also the giver of the Spirit, it seems unfitting to say that He was made under the Law. I answer that “to be under the Law” can be understood in two ways. In one way, “under” denotes the mere observance of the Law. In this sense, Christ was under the Law, because He was circumcised and presented in the temple: “I am not come to destroy but to fulfill” (Matthew 5:17). In another way, “under” denotes oppression. In this sense, one is under the Law if one is oppressed by fear of it. Neither Christ nor spiritual people are under the Law in this second way.

Finally, when the Apostle says, that he might redeem them who were under the law, he presents the fruit of Christ’s work. The reason He willed His people to be subject for a time was so that they might become great and free heirs. The Apostle mentions two aspects of this fruit.

First is the fruit of freedom from subjection. He says, that he might redeem them who were under the law—that is, from under the curse and burden of the Law. As he says elsewhere, “Christ hath redeemed us from the curse of the law, being made a curse for us” (Galatians 3:13). Second is the fruit of being made great, inasmuch as we are adopted as sons of God by receiving the Spirit of God and being conformed to Him: “Now if any man have not the Spirit of Christ, he is none of his” (Romans 8:9).

This adoption is related to Christ in a special way, because we cannot become adopted sons unless we are conformed to the natural Son: “For whom he foreknew, he also predestinated to be made conformable to the image of his Son” (Romans 8:29). With this in mind, the Apostle concludes, that we might receive the adoption of sons. This means that through the natural Son of God, we are made adopted sons by grace through Christ.