It is evident from a consideration of the mode of living things that woman properly formed part of the first creation, in aid of generation. For there are some things which have not the power of reproduction except through the agency of another species; and certain plants and animals which are generated spontaneously without seed. Others have the active and passive virtues combined; as plants, which are produced from seed. But it belongs to the perfect animal to have the generative power by mode of sex; active in the male and passive in the female; and because men have a nobler work to which their life is principally ordered, the sexes are only united in the time of generation. Since, therefore, man was ordained to a nobler work, namely, that of the intellect, it was fitting that there should be in him a distinction of these powers; and principally that he might love the woman who was produced from himself, and that they might be united in the work of generation. Thus after the production of the woman it is said immediately: "They were two in one flesh."
And it was fitting that in the original institution woman should be formed from man (which was not the case with the lower animals), first, in order to preserve the dignity of the man, that he might be the principle of the entire species, as God is the Principle of the entire universe; secondly, that he might the better love his wife, because knowing her to have been produced from himself, and that they might always remain companions; thirdly, because they are not united for the purpose of generation only, like other animals, but for the sake of domestic life; and fourthly, because we have herein a figure of the Church, which takes its origin from Christ; as the apostle says to the Ephesians (Chapter 5).
Moreover, woman was made from the side of man to indicate social companionship; not from his head, lest she should seem to be mistress over him, nor from his feet, lest she should appear to be his servant: we may add, also, that it signified the Church, which emanated from the side of Christ.
Woman was made immediately by God; for since she was formed of other matter than that from which man is usually generated, she could have been made by God only; but whether or not any ministry of angels intervened is unknown.
- text taken from Compendium of the Summa Theologica of Saint Thomas Aquinas, by Bishop Berardus Bongiovanni