Summa Theologica, by St. Thomas Aquinas, [1947], at sacred-texts.com
We must next consider the production of the woman. Under this head there are four points of inquiry:
(1) Whether the woman should have been made in that first production of things?
(2) Whether the woman should have been made from man?
(3) Whether of man's rib?
(4) Whether the woman was made immediately by God?
Objection 1: It would seem that the woman should not have been made in the first production of things. For the Philosopher says (De Gener. ii, 3), that "the female is a misbegotten male." But nothing misbegotten or defective should have been in the first production of things. Therefore woman should not have been made at that first production.
Objection 2: Further, subjection and limitation were a result of sin, for to the woman was it said after sin (Gn. 3:16): "Thou shalt be under the man's power"; and Gregory says that, "Where there is no sin, there is no inequality." But woman is naturally of less strength and dignity than man; "for the agent is always more honorable than the patient," as Augustine says (Gen. ad lit. xii, 16). Therefore woman should not have been made in the first production of things before sin.
Objection 3: Further, occasions of sin should be cut off. But God foresaw that the woman would be an occasion of sin to man. Therefore He should not have made woman.
On the contrary, It is written (Gn. 2:18): "It is not good for man to be alone; let us make him a helper like to himself."
I answer that, It was necessary for woman to be made, as the Scripture says, as a "helper" to man; not, indeed, as a helpmate in other works, as some say, since man can be more efficiently helped by another man in other works; but as a helper in the work of generation. This can be made clear if we observe the mode of generation carried out in various living things. Some living things do not possess in themselves the power of generation, but are generated by some other specific agent, such as some plants and animals by the influence of the heavenly bodies, from some fitting matter and not from seed: others possess the active and passive generative power together; as we see in plants which are generated from seed; for the noblest vital function in plants is generation. Wherefore we observe that in these the active power of generation invariably accompanies the passive power. Among perfect animals the active power of generation belongs to the male sex, and the passive power to the female. And as among animals there is a vital operation nobler than generation, to which their life is principally directed; therefore the male sex is not found in continual union with the female in perfect animals, but only at the time of coition; so that we may consider that by this means the male and female are one, as in plants they are always united; although in some cases one of them preponderates, and in some the other. But man is yet further ordered to a still nobler vital action, and that is intellectual operation. Therefore there was greater reason for the distinction of these two forces in man; so that the female should be produced separately from the male; although they are carnally united for generation. Therefore directly after the formation of woman, it was said: "And they shall be two in one flesh" (Gn. 2:24).
Reply to Objection 1: As regards the individual nature, woman is defective and misbegotten, for the active force in the male seed tends to the production of a perfect likeness in the masculine sex; while the production of woman comes from defect in the active force or from some material indisposition, or even from some external influence; such as that of a south wind, which is moist, as the Philosopher observes (De Gener. Animal. iv, 2). On the other hand, as regards human nature in general, woman is not misbegotten, but is included in nature's intention as directed to the work of generation. Now the general intention of nature depends on God, Who is the universal Author of nature. Therefore, in producing nature, God formed not only the male but also the female.
Reply to Objection 2: Subjection is twofold. One is servile, by virtue of which a superior makes use of a subject for his own benefit; and this kind of subjection began after sin. There is another kind of subjection which is called economic or civil, whereby the superior makes use of his subjects for their own benefit and good; and this kind of subjection existed even before sin. For good order would have been wanting in the human family if some were not governed by others wiser than themselves. So by such a kind of subjection woman is naturally subject to man, because in man the discretion of reason predominates. Nor is inequality among men excluded by the state of innocence, as we shall prove (Q[96], A[3]).
Reply to Objection 3: If God had deprived the world of all those things which proved an occasion of sin, the universe would have been imperfect. Nor was it fitting for the common good to be destroyed in order that individual evil might be avoided; especially as God is so powerful that He can direct any evil to a good end.
Objection 1: It would seem that woman should not have been made from man. For sex belongs both to man and animals. But in the other animals the female was not made from the male. Therefore neither should it have been so with man.
Objection 2: Further, things of the same species are of the same matter. But male and female are of the same species. Therefore, as man was made of the slime of the earth, so woman should have been made of the same, and not from man.
Objection 3: Further, woman was made to be a helpmate to man in the work of generation. But close relationship makes a person unfit for that office; hence near relations are debarred from intermarriage, as is written (Lev. 18:6). Therefore woman should not have been made from man.
On the contrary, It is written (Ecclus. 17:5): "He created of him," that is, out of man, "a helpmate like to himself," that is, woman.
I answer that, When all things were first formed, it was more suitable for the woman to be made from man that (for the female to be from the male) in other animals. First, in order thus to give the first man a certain dignity consisting in this, that as God is the principle of the whole universe, so the first man, in likeness to God, was the principle of the whole human race. Wherefore Paul says that "God made the whole human race from one" (Acts 17:26). Secondly, that man might love woman all the more, and cleave to her more closely, knowing her to be fashioned from himself. Hence it is written (Gen. 2:23, 24): "She was taken out of man, wherefore a man shall leave father and mother, and shall cleave to his wife." This was most necessary as regards the human race, in which the male and female live together for life; which is not the case with other animals. Thirdly, because, as the Philosopher says (Ethic. viii, 12), the human male and female are united, not only for generation, as with other animals, but also for the purpose of domestic life, in which each has his or her particular duty, and in which the man is the head of the woman. Wherefore it was suitable for the woman to be made out of man, as out of her principle. Fourthly, there is a sacramental reason for this. For by this is signified that the Church takes her origin from Christ. Wherefore the Apostle says (Eph. 5:32): "This is a great sacrament; but I speak in Christ and in the Church."
Reply OBJ 1 is clear from the foregoing.
Reply to Objection 2: Matter is that from which something is made. Now created nature has a determinate principle; and since it is determined to one thing, it has also a determinate mode of proceeding. Wherefore from determinate matter it produces something in a determinate species. On the other hand, the Divine Power, being infinite, can produce things of the same species out of any matter, such as a man from the slime of the earth, and a woman from out of man.
Reply to Objection 3: A certain affinity arises from natural generation, and this is an impediment to matrimony. Woman, however, was not produced from man by natural generation, but by the Divine Power alone. Wherefore Eve is not called the daughter of Adam; and so this argument does not prove.
Objection 1: It would seem that the woman should not have been formed from the rib of man. For the rib was much smaller than the woman's body. Now from a smaller thing a larger thing can be made only---either by addition (and then the woman ought to have been described as made out of that which was added, rather than out of the rib itself)---or by rarefaction, because, as Augustine says (Gen. ad lit. x): "A body cannot increase in bulk except by rarefaction." But the woman's body is not more rarefied than man's---at least, not in the proportion of a rib to Eve's body. Therefore Eve was not formed from a rib of Adam.
Objection 2: Further, in those things which were first created there was nothing superfluous. Therefore a rib of Adam belonged to the integrity of his body. So, if a rib was removed, his body remained imperfect; which is unreasonable to suppose.
Objection 3: Further, a rib cannot be removed from man without pain. But there was no pain before sin. Therefore it was not right for a rib to be taken from the man, that Eve might be made from it.
On the contrary, It is written (Gn. 2:22): "God built the rib, which He took from Adam, into a woman."
I answer that, It was right for the woman to be made from a rib of man. First, to signify the social union of man and woman, for the woman should neither "use authority over man," and so she was not made from his head; nor was it right for her to be subject to man's contempt as his slave, and so she was not made from his feet. Secondly, for the sacramental signification; for from the side of Christ sleeping on the Cross the Sacraments flowed---namely, blood and water---on which the Church was established.
Reply to Objection 1: Some say that the woman's body was formed by a material increase, without anything being added; in the same way as our Lord multiplied the five loaves. But this is quite impossible. For such an increase of matter would either be by a change of the very substance of the matter itself, or by a change of its dimensions. Not by change of the substance of the matter, both because matter, considered in itself, is quite unchangeable, since it has a potential existence, and has nothing but the nature of a subject, and because quantity and size are extraneous to the essence of matter itself. Wherefore multiplication of matter is quite unintelligible, as long as the matter itself remains the same without anything added to it; unless it receives greater dimensions. This implies rarefaction, which is for the same matter to receive greater dimensions, as the Philosopher says (Phys. iv). To say, therefore, that the same matter is enlarged, without being rarefied, is to combine contradictories ---viz. the definition with the absence of the thing defined.
Wherefore, as no rarefaction is apparent in such multiplication of matter, we must admit an addition of matter: either by creation, or which is more probable, by conversion. Hence Augustine says (Tract. xxiv in Joan.) that "Christ filled five thousand men with five loaves, in the same way as from a few seeds He produces the harvest of corn"---that is, by transformation of the nourishment. Nevertheless, we say that the crowds were fed with five loaves, or that woman was made from the rib, because an addition was made to the already existing matter of the loaves and of the rib.
Reply to Objection 2: The rib belonged to the integral perfection of Adam, not as an individual, but as the principle of the human race; just as the semen belongs to the perfection of the begetter, and is released by a natural and pleasurable operation. Much more, therefore, was it possible that by the Divine power the body of the woman should be produced from the man's rib.
From this it is clear how to answer the third objection.
Objection 1: It would seem that the woman was not formed immediately by God. For no individual is produced immediately by God from another individual alike in species. But the woman was made from a man who is of the same species. Therefore she was not made immediately by God.
Objection 2: Further, Augustine (De Trin. iii, 4) says that corporeal things are governed by God through the angels. But the woman's body was formed from corporeal matter. Therefore it was made through the ministry of the angels, and not immediately by God.
Objection 3: Further, those things which pre-exist in creatures as to their causal virtues are produced by the power of some creature, and not immediately by God. But the woman's body was produced in its causal virtues among the first created works, as Augustine says (Gen. ad lit. ix, 15). Therefore it was not produced immediately by God.
On the contrary, Augustine says, in the same work: "God alone, to Whom all nature owes its existence, could form or build up the woman from the man's rib."
I answer that, As was said above (A[2], ad 2), the natural generation of every species is from some determinate matter. Now the matter whence man is naturally begotten is the human semen of man or woman. Wherefore from any other matter an individual of the human species cannot naturally be generated. Now God alone, the Author of nature, can produce an effect into existence outside the ordinary course of nature. Therefore God alone could produce either a man from the slime of the earth, or a woman from the rib of man.
Reply to Objection 1: This argument is verified when an individual is begotten, by natural generation, from that which is like it in the same species.
Reply to Objection 2: As Augustine says (Gen. ad lit. ix, 15), we do not know whether the angels were employed by God in the formation of the woman; but it is certain that, as the body of man was not formed by the angels from the slime of the earth, so neither was the body of the woman formed by them from the man's rib.
Reply to Objection 3: As Augustine says (Gen. ad lit. ix, 18): "The first creation of things did not demand that woman should be made thus; it made it possible for her to be thus made." Therefore the body of the woman did indeed pre-exist in these causal virtues, in the things first created; not as regards active potentiality, but as regards a potentiality passive in relation to the active potentiality of the Creator.