Thomas Aquinas, Summa Theologiae

Objection 1: It would seem that the flesh of Christ was not conceived of the Virgin's purest blood: For it is said in the collect (Feast of the Annunciation) that God "willed that His Word should take flesh from a Virgin." But flesh differs from blood. Therefore Christ's body was not taken from the Virgin's blood.

Objection 2: Further, as the woman was miraculously formed from the man, so Christ's body was formed miraculously from the Virgin. But the woman is not said to have been formed from the man's blood, but rather from his flesh and bones, according to Gn. 2:23: "This now is bone of my bones, and flesh of my flesh." It seems therefore that neither should Christ's body have been formed from the Virgin's blood, but from her flesh and bones.

Objection 3: Further, Christ's body was of the same species as other men's bodies. But other men's bodies are not formed from the purest blood but from the semen and the menstrual blood. Therefore it seems that neither was Christ's body conceived of the purest blood of the Virgin.

On the contrary, Damascene says (De Fide Orth. iii) that "the Son of God, from the Virgin's purest blood, formed Himself flesh, animated with a rational soul."

I answer that, As stated above (Article 4), in Christ's conception His being born of a woman was in accordance with the laws of nature, but that He was born of a virgin was above the laws of nature. Now, such is the law of nature that in the generation of an animal the female supplies the matter, while the male is the active principle of generation; as the Philosopher proves (De Gener. Animal. i). But a woman who conceives of a man is not a virgin. And consequently it belongs to the supernatural mode of Christ's generation, that the active principle of generation was the supernatural power of God: but it belongs to the natural mode of His generation, that the matter from which His body was conceived is similar to the matter which other women supply for the conception of their offspring. Now, this matter, according to the Philosopher (De Gener. Animal.), is the woman's blood, not any of her blood, but brought to a more perfect stage of secretion by the mother's generative power, so as to be apt for conception. And therefore of such matter was Christ's body conceived.

Reply to Objection 1: Since the Blessed Virgin was of the same nature as other women, it follows that she had flesh and bones of the same nature as theirs. Now, flesh and bones in other women are actual parts of the body, the integrity of which results therefrom: and consequently they cannot be taken from the body without its being corrupted or diminished. But as Christ came to heal what was corrupt, it was not fitting that He should bring corruption or diminution to the integrity of His Mother. Therefore it was becoming that Christ's body should be formed not from the flesh or bones of the Virgin, but from her blood, which as yet is not actually a part, but is potentially the whole, as stated in De Gener. Animal. i. Hence He is said to have taken flesh from the Virgin, not that the matter from which His body was formed was actual flesh, but blood, which is flesh potentially.

Reply to Objection 2: As stated in the 1, Question 92, Article 3, ad 2, Adam, through being established as a kind of principle of human nature, had in his body a certain proportion of flesh and bone, which belonged to him, not as an integral part of his personality, but in regard to his state as a principle of human nature. And from this was the woman formed, without detriment to the man. But in the Virgin's body there was nothing of this sort, from which Christ's body could be formed without detriment to His Mother's body.

Reply to Objection 3: Woman's semen is not apt for generation, but is something imperfect in the seminal order, which, on account of the imperfection of the female power, it has not been possible to bring to complete seminal perfection. Consequently this semen is not the necessary matter of conception; as the Philosopher says (De Gener. Animal. i): wherefore there was none such in Christ's conception: all the more since, though it is imperfect in the seminal order, a certain concupiscence accompanies its emission, as also that of the male semen: whereas in that virginal conception there could be no concupiscence. Wherefore Damascene says (De Fide Orth. iii) that Christ's body was not conceived "seminally." But the menstrual blood, the flow of which is subject to monthly periods, has a certain natural impurity of corruption: like other superfluities, which nature does not heed, and therefore expels. Of such menstrual blood infected with corruption and repudiated by nature, the conception is not formed; but from a certain secretion of the pure blood which by a process of elimination is prepared for conception, being, as it were, more pure and more perfect than the rest of the blood. Nevertheless, it is tainted with the impurity of lust in the conception of other men: inasmuch as by sexual intercourse this blood is drawn to a place apt for conception. This, however, did not take place in Christ's conception: because this blood was brought together in the Virgin's womb and fashioned into a child by the operation of the Holy Ghost. Therefore is Christ's body said to be "formed of the most chaste and purest blood of the Virgin."

Articulus 5

Argumentum 1

Ad quintum sic proceditur. Videtur quod caro christi non fuerit concepta ex purissimis sanguinibus virginis.

Dicitur enim in collecta quod deus verbum suum de virgine carnem sumere voluit.

Sed caro differt a sanguine. Ergo corpus christi non est sumptum de sanguine virginis.

Argumentum 2

Praeterea, sicut mulier formata est miraculose de viro, ita corpus christi miraculose formatum est de virgine. Sed mulier non dicitur esse formata de sanguine viri, sed magis de carne et ossibus eius, secundum illud quod dicitur Gen. II, hoc nunc os ex ossibus meis, et caro de carne mea.

Ergo videtur quod nec etiam corpus christi formari debuerit de sanguine virginis, sed de carnibus et ossibus eius.

Argumentum 3

Praeterea, corpus christi fuit eiusdem speciei cum corporibus aliorum hominum. Sed corpora aliorum hominum non formantur ex purissimo sanguine, sed ex semine et sanguine menstruo. Ergo videtur quod nec etiam corpus christi fuerit conceptum ex purissimis sanguinibus virginis.

Sed Contra

Sed contra est quod Damascenus dicit, in III libro, quod filius dei construxit sibi ipsi ex castis et purissimis sanguinibus virginis carnem animatam anima rationali.

Corpus

Respondeo dicendum quod, sicut supra dictum est, in conceptione christi fuit secundum conditionem naturae quod est natus ex femina, sed supra conditionem naturae quod est natus ex virgine.

Habet autem hoc naturalis conditio, quod in generatione animalis femina materiam ministret, ex parte autem maris sit activum principium in generatione, sicut probat philosophus, in libro de generat. Animal..

Femina autem quae ex mare concipit, non est virgo.

Et ideo ad supernaturalem modum generationis christi pertinet quod activum principium in generatione illa fuerit virtus supernaturalis divina, sed ad naturalem modum generationis eius pertinet quod materia de qua corpus eius conceptum est, sit conformis materiae quam aliae feminae subministrant ad conceptionem prolis. Haec autem materia, secundum philosophum, in libro de generat. Animal., est sanguis mulieris, non quicumque, sed perductus ad quandam ampliorem digestionem per virtutem generativam matris, ut sit materia apta ad conceptum.

Et ideo ex tali materia fuit corpus christi conceptum.

Ad 1

Ad primum ergo dicendum quod, cum beata virgo fuerit eiusdem naturae cum aliis feminis, consequens est quod habuerit carnem et ossa eiusdem naturae. Carnes autem et ossa in aliis feminis sunt actuales corporis partes, ex quibus constituitur integritas corporis, et ideo subtrahi non possunt sine corruptione corporis vel deminutione. Christus autem, qui venerat corrupta reparare, nullam corruptionem aut deminutionem integritati matris eius inferre debuit. Et ideo non debuit corpus christi formari de carne vel ossibus virginis, sed de sanguine, qui nondum est actu pars, sed est potentia totum, ut dicitur in libro de generat. Animal.. Et ideo dicitur carnem de virgine sumpsisse, non quod materia corporis fuerit actu caro, sed sanguis, qui est potentia caro.

Ad 2

Ad secundum dicendum quod, sicut in prima parte dictum est, Adam, quia institutus erat ut principium quoddam humanae naturae, habebat in suo corpore aliquid carnis et ossis quod non pertinebat ad integritatem personalem ipsius, sed solum inquantum erat naturae humanae principium. Et de tali formata est mulier, absque viri detrimento. Sed nihil tale fuit in corpore virginis, ex quo corpus christi posset formari sine corruptione materni corporis.

Ad 3

Ad tertium dicendum quod semen feminae non est generationi aptum, sed est quiddam imperfectum in genere seminis, quod non potuit produci ad perfectum seminis complementum, propter imperfectionem virtutis femineae. Et ideo tale semen non est materia quae de necessitate requiratur ad conceptum, sicut philosophus dicit, in libro de generat. Animal..

Et ideo in conceptione christi non fuit, praesertim quia, licet sit imperfectum in genere seminis, tamen cum quadam concupiscentia resolvitur, sicut et semen maris; in illo autem conceptu virginali concupiscentia locum habere non potuit.

Et ideo Damascenus dicit quod corpus christi non seminaliter conceptum est.

Sanguis autem menstruus, quem feminae per singulos menses emittunt, impuritatem quandam naturalem habet corruptionis, sicut et ceterae superfluitates, quibus natura non indiget, sed eas expellit. Ex tali autem menstruo corruptionem habente, quod natura repudiat, non formatur conceptus, sed hoc est purgamentum quoddam illius puri sanguinis qui digestione quadam est praeparatus ad conceptum, quasi purior et perfectior alio sanguine. Habet tamen impuritatem libidinis in conceptione aliorum hominum, inquantum ex ipsa commixtione maris et feminae talis sanguis ad locum generationi congruum attrahitur. Sed hoc in conceptione christi non fuit, quia operatione spiritus sancti talis sanguis in utero virginis adunatus est et formatus in prolem. Et ideo dicitur corpus christi ex castissimis et purissimis sanguinibus virginis formatum.