Thomas Aquinas, Summa Theologiae

Objection 1: It would seem that the semen is not produced from the surplus food, but from the substance of the begetter. For Damascene says (De Fide Orth. i, 8) that "generation is a work of nature, producing, from the substance of the begetter, that which is begotten." But that which is generated is produced from the semen. Therefore the semen is produced from the substance of the begetter.

Objection 2: Further, the son is like his father, in respect of that which he receives from him. But if the semen from which something is generated, is produced from the surplus food, a man would receive nothing from his grandfather and his ancestors in whom the food never existed. Therefore a man would not be more like to his grandfather or ancestors, than to any other men.

Objection 3: Further, the food of the generator is sometimes the flesh of cows, pigs and suchlike. If therefore, the semen were produced from surplus food, the man begotten of such semen would be more akin to the cow and the pig, than to his father or other relations.

Objection 4: Further, Augustine says (Gen. ad lit. x, 20) that we were in Adam "not only by seminal virtue, but also in the very substance of the body." But this would not be, if the semen were produced from surplus food. Therefore the semen is not produced therefrom.

On the contrary, The Philosopher proves in many ways (De Gener. Animal. i, 18) that "the semen is surplus food."

I answer that, This question depends in some way on what has been stated above (Article 1; Question 118, Article 1). For if human nature has a virtue for the communication of its form to alien matter not only in another, but also in its own subject; it is clear that the food which at first is dissimilar, becomes at length similar through the form communicated to it. Now it belongs to the natural order that a thing should be reduced from potentiality to act gradually: hence in things generated we observe that at first each is imperfect and is afterwards perfected. But it is clear that the common is to the proper and determinate, as imperfect is to perfect: therefore we see that in the generation of an animal, the animal is generated first, then the man or the horse. So therefore food first of all receives a certain common virtue in regard to all the parts of the body, which virtue is subsequently determinate to this or that part.

Now it is not possible that the semen be a kind of solution from what is already transformed into the substance of the members. For this solution, if it does not retain the nature of the member it is taken from, it would no longer be of the nature of the begetter, and would be due to a process of corruption; and consequently it would not have the power of transforming something else into the likeness of that nature. But if it retained the nature of the member it is taken from, then, since it is limited to a certain part of the body, it would not have the power of moving towards (the production of) the whole nature, but only the nature of that part. Unless one were to say that the solution is taken from all the parts of the body, and that it retains the nature of each part. Thus the semen would be a small animal in act; and generation of animal from animal would be a mere division, as mud is generated from mud, and as animals which continue to live after being cut in two: which is inadmissible.

It remains to be said, therefore, that the semen is not something separated from what was before the actual whole; rather is it the whole, though potentially, having the power, derived from the soul of the begetter, to produce the whole body, as stated above (Article 1; Question 108, Article 1). Now that which is in potentiality to the whole, is that which is generated from the food, before it is transformed into the substance of the members. Therefore the semen is taken from this. In this sense the nutritive power is said to serve the generative power: because what is transformed by the nutritive power is employed as semen by the generative power. A sign of this, according to the Philosopher, is that animals of great size, which require much food, have little semen in proportion to the size of their bodies, and generated seldom; in like manner fat men, and for the same reason.

Reply to Objection 1: Generation is from the substance of the begetter in animals and plants, inasmuch as the semen owes its virtue to the form of the begetter, and inasmuch as it is in potentiality to the substance.

Reply to Objection 2: The likeness of the begetter to the begotten is on account not of the matter, but of the form of the agent that generates its like. Wherefore in order for a man to be like his grandfather, there is no need that the corporeal seminal matter should have been in the grandfather; but that there be in the semen a virtue derived from the soul of the grandfather through the father. In like manner the third objection is answered. For kinship is not in relation to matter, but rather to the derivation of the forms.

Reply to Objection 4: These words of Augustine are not to be understood as though the immediate seminal virtue, or the corporeal substance from which this individual was formed were actually in Adam: but so that both were in Adam as in principle. For even the corporeal matter, which is supplied by the mother, and which he calls the corporeal substance, is originally derived from Adam: and likewise the active seminal power of the father, which is the immediate seminal virtue (in the production) of this man.

But Christ is said to have been in Adam according to the "corporeal substance," not according to the seminal virtue. Because the matter from which His Body was formed, and which was supplied by the Virgin Mother, was derived from Adam; whereas the active virtue was not derived from Adam, because His Body was not formed by the seminal virtue of a man, but by the operation of the Holy Ghost. For "such a birth was becoming to Him," , WHO IS ABOVE ALL GOD FOR EVER BLESSED. Amen.

Articulus 2

Argumentum 1

Ad secundum sic proceditur. Videtur quod semen non sit de superfluo alimenti, sed de substantia generantis.

Dicit enim Damascenus quod generatio est opus naturae ex substantia generantis producens quod generatur.

Sed id quod generatur, generatur ex semine.

Ergo semen est de substantia generantis.

Argumentum 2

Praeterea, secundum hoc filius assimilatur patri, quod ab eo aliquid accipit. Sed si semen ex quo aliquid generatur, sit de superfluo alimenti; nihil acciperet aliquis ab avo et praecedentibus, in quibus hoc alimentum nullo modo fuit.

Ergo non assimilaretur aliquis avo et praecedentibus, magis quam aliis hominibus.

Argumentum 3

Praeterea, alimentum hominis generantis quandoque est ex carnibus bovis, vel porci, et aliorum huiusmodi. Si igitur semen esset de superfluo alimenti, homo generatus ex semine maiorem affinitatem haberet cum bove et porco, quam cum patre et aliis consanguineis.

Argumentum 4

Praeterea, Augustinus dicit, X super Gen. Ad litt., quod nos fuimus in Adam non solum secundum seminalem rationem, sed etiam secundum corpulentam substantiam.

Hoc autem non esset, si semen esset ex superfluo alimenti.

Ergo semen non est superfluo alimenti.

Sed Contra

Sed contra est quod philosophus probat multipliciter, in libro de generat. Animal., quod semen est superfluum alimenti.

Corpus

Respondeo dicendum quod ista quaestio aliqualiter dependet ex praemissis.

Si enim in natura humana est virtus ad communicandum suam formam materiae alienae non solum in alio, sed etiam in ipso; manifestum est quod alimentum, quod est in principio dissimile, in fine fit simile per formam communicatam. Est autem naturalis ordo ut aliquid gradatim de potentia reducatur in actum, et ideo in his quae generantur, invenimus quod primo unumquodque est imperfectum, et postea perficitur. Manifestum est autem quod commune se habet ad proprium et determinatum, ut imperfectum ad perfectum, et ideo videmus quod in generatione animalis prius generatur animal, quam homo vel equus. Sic igitur et ipsum alimentum primo quidem accipit quandam virtutem communem respectu omnium partium corporis, et in fine determinatur ad hanc partem vel ad illam. Non autem est possibile quod accipiatur pro semine id quod iam conversum est in substantiam membrorum, per quandam resolutionem. Quia illud resolutum, si non retineret naturam eius a quo resolvitur, tunc iam esset recedens a natura generantis, quasi in via corruptionis existens; et sic non haberet virtutem convertendi aliud in similem naturam. Si vero retineret naturam eius a quo resolvitur, tunc, cum esset contractum ad determinatam partem, non haberet virtutem movendi ad naturam totius, sed solum ad naturam partis. Nisi forte quis dicat quod esset resolutum ab omnibus partibus corporis, et quod retineat naturam omnium partium. Et sic semen esset quasi quoddam parvum animal in actu; et generatio animalis ex animali non esset nisi per divisionem, sicut lutum generatur ex luto, et sicut accidit in animalibus quae decisa vivunt. Hoc autem est inconveniens. Relinquitur ergo quod semen non sit decisum ab eo quod erat actu totum; sed magis sit in potentia totum, habens virtutem ad productionem totius corporis, derivatam an anima generantis, ut supra dictum est.

Hoc autem quod est in potentia ad totum, est illud quod generatur ex alimento, antequam convertatur in substantiam membrorum. Et ideo ex hoc semen accipitur. Et secundum hoc, virtus nutritiva dicitur deservire generativae, quia id quod est conversum per virtutem nutritivam, accipitur a virtute generativa ut semen.

Et huius signum ponit philosophus, quod animalia magni corporis, quae indigent multo nutrimento, sunt pauci seminis secundum quantitatem sui corporis, et paucae generationis; et similiter homines pingues sunt pauci seminis, propter eandem causam.

Ad 1

Ad primum ergo dicendum quod generatio est de substantia generantis in animalibus et plantis, inquantum semen habet virtutem ex forma generantis, et inquantum est in potentia ad substantiam ipsius.

Ad 2

Ad secundum dicendum quod assimilatio generantis ad genitum non fit propter materiam, sed propter formam agentis, quod generat sibi simile. Unde non oportet ad hoc quod aliquis assimiletur avo, quod materia corporalis seminis fuerit in avo; sed quod sit in semine aliqua virtus derivata ab anima avi, mediante patre.

Ad 3

Et similiter dicendum est ad tertium. Nam affinitas non attenditur secundum materiam, sed magis secundum derivationem formae.

Ad 4

Ad quartum dicendum quod verbum Augustini non est sic intelligendum, quasi in Adam actu fuerit aut seminalis ratio huius hominis propinqua, aut corpulenta eius substantia, sed utrumque fuit in Adam secundum originem. Nam et materia corporalis, quae ministrata est a matre, quam vocat corpulentam substantiam, derivatur originaliter ab Adam, et similiter virtus activa existens in semine patris, quae est huius hominis propinqua ratio seminalis.

Sed christus dicitur fuisse in Adam secundum corpulentam substantiam, sed non secundum seminalem rationem.

Quia materia corporis eius, quae ministrata est a matre virgine, derivata est ab Adam, sed virtus activa non est derivata ab Adam, quia corpus eius non est formatum per virtutem virilis seminis, sed operatione spiritus sancti. Talis enim partus decebat eum, qui est super omnia benedictus deus in saecula. Amen.