Thomas Aquinas, Summa Theologiae

Objection 1: It would seem that the intellectual soul is produced from the semen. For it is written (Gn. 46:26): "All the souls that came out of thigh, sixty-six." But nothing is produced from the thigh of a man, except from the semen. Therefore the intellectual soul is produced from the semen.

Objection 2: Further, as shown above (Question 76, Article 3), the intellectual, sensitive, and nutritive souls are, in substance, one soul in man. But the sensitive soul in man is generated from the semen, as in other animals; wherefore the Philosopher says (De Gener. Animal. ii, 3) that the animal and the man are not made at the same time, but first of all the animal is made having a sensitive soul. Therefore also the intellectual soul is produced from the semen.

Objection 3: Further, it is one and the same agent whose action is directed to the matter and to the form: else from the matter and the form there would not result something simply one. But the intellectual soul is the form of the human body, which is produced by the power of the semen. Therefore the intellectual soul also is produced by the power of the semen.

Objection 4: Further, man begets his like in species. But the human species is constituted by the rational soul. Therefore the rational soul is from the begetter.

Objection 5: Further, it cannot be said that God concurs in sin. But if the rational soul be created by God, sometimes God concurs in the sin of adultery, since sometimes offspring is begotten of illicit intercourse. Therefore the rational soul is not created by God.

On the contrary, It is written in De Eccl. Dogmat. xiv that "the rational soul is not engendered by coition."

I answer that, It is impossible for an active power existing in matter to extend its action to the production of an immaterial effect. Now it is manifest that the intellectual principle in man transcends matter; for it has an operation in which the body takes no part whatever. It is therefore impossible for the seminal power to produce the intellectual principle.

Again, the seminal power acts by virtue of the soul of the begetter according as the soul of the begetter is the act of the body, making use of the body in its operation. Now the body has nothing whatever to do in the operation of the intellect. Therefore the power of the intellectual principle, as intellectual, cannot reach the semen. Hence the Philosopher says (De Gener. Animal. ii, 3): "It follows that the intellect alone comes from without."

Again, since the intellectual soul has an operation independent of the body, it is subsistent, as proved above (Question 75, Article 2): therefore to be and to be made are proper to it. Moreover, since it is an immaterial substance it cannot be caused through generation, but only through creation by God. Therefore to hold that the intellectual soul is caused by the begetter, is nothing else than to hold the soul to be non-subsistent and consequently to perish with the body. It is therefore heretical to say that the intellectual soul is transmitted with the semen.

Reply to Objection 1: In the passage quoted, the part is put instead of the whole, the soul for the whole man, by the figure of synecdoche.

Reply to Objection 2: Some say that the vital functions observed in the embryo are not from its soul, but from the soul of the mother; or from the formative power of the semen. Both of these explanations are false; for vital functions such as feeling, nourishment, and growth cannot be from an extrinsic principle. Consequently it must be said that the soul is in the embryo; the nutritive soul from the beginning, then the sensitive, lastly the intellectual soul.

Therefore some say that in addition to the vegetative soul which existed first, another, namely the sensitive, soul supervenes; and in addition to this, again another, namely the intellectual soul. Thus there would be in man three souls of which one would be in potentiality to another. This has been disproved above (Question 76, Article 3).

Therefore others say that the same soul which was at first merely vegetative, afterwards through the action of the seminal power, becomes a sensitive soul; and finally this same soul becomes intellectual, not indeed through the active seminal power, but by the power of a higher agent, namely God enlightening (the soul) from without. For this reason the Philosopher says that the intellect comes from without. But this will not hold. First, because no substantial form is susceptible of more or less; but addition of greater perfection constitutes another species, just as the addition of unity constitutes another species of number. Now it is not possible for the same identical form to belong to different species. Secondly, because it would follow that the generation of an animal would be a continuous movement, proceeding gradually from the imperfect to the perfect, as happens in alteration. Thirdly, because it would follow that the generation of a man or an animal is not generation simply, because the subject thereof would be a being in act. For if the vegetative soul is from the beginning in the matter of offspring, and is subsequently gradually brought to perfection; this will imply addition of further perfection without corruption of the preceding perfection. And this is contrary to the nature of generation properly so called. Fourthly, because either that which is caused by the action of God is something subsistent: and thus it must needs be essentially distinct from the pre-existing form, which was non-subsistent; and we shall then come back to the opinion of those who held the existence of several souls in the body---or else it is not subsistent, but a perfection of the pre-existing soul: and from this it follows of necessity that the intellectual soul perishes with the body, which cannot be admitted.

There is again another explanation, according to those who held that all men have but one intellect in common: but this has been disproved above (Question 76, Article 2).

We must therefore say that since the generation of one thing is the corruption of another, it follows of necessity that both in men and in other animals, when a more perfect form supervenes the previous form is corrupted: yet so that the supervening form contains the perfection of the previous form, and something in addition. It is in this way that through many generations and corruptions we arrive at the ultimate substantial form, both in man and other animals. This indeed is apparent to the senses in animals generated from putrefaction. We conclude therefore that the intellectual soul is created by God at the end of human generation, and this soul is at the same time sensitive and nutritive, the pre-existing forms being corrupted.

Reply to Objection 3: This argument holds in the case of diverse agents not ordered to one another. But where there are many agents ordered to one another, nothing hinders the power of the higher agent from reaching to the ultimate form; while the powers of the inferior agents extend only to some disposition of matter: thus in the generation of an animal, the seminal power disposes the matter, but the power of the soul gives the form. Now it is manifest from what has been said above (Question 105, Article 5; Question 110, Article 1) that the whole of corporeal nature acts as the instrument of a spiritual power, especially of God. Therefore nothing hinders the formation of the body from being due to a corporeal power, while the intellectual soul is from God alone.

Reply to Objection 4: Man begets his like, forasmuch as by his seminal power the matter is disposed for the reception of a certain species of form.

Reply to Objection 5: In the action of the adulterer, what is of nature is good; in this God concurs. But what there is of inordinate lust is evil; in this God does not concur.

Articulus 2

Argumentum 1

Ad secundum sic proceditur. Videtur quod anima intellectiva causetur ex semine.

Dicitur enim Gen. XLVI, cunctae animae quae egressae sunt de femore Iacob, sexaginta sex.

Sed nihil egreditur de femore hominis, nisi inquantum causatur ex semine. Ergo anima intellectiva causatur ex semine.

Argumentum 2

Praeterea, sicut supra ostensum est, in homine est una et eadem anima secundum substantiam, intellectiva, sensitiva et nutritiva.

Sed anima sensitiva in homine generatur ex semine, sicut in aliis animalibus, unde et philosophus dicit in libro de generat. Animal., quod non simul fit animal et homo, sed prius fit animal habens animam sensitivam. Ergo et anima intellectiva causatur ex semine.

Argumentum 3

Praeterea, unum et idem agens, est cuius actio terminatur ad formam, et materiam, alioquin ex forma et materia non fieret unum simpliciter. Sed anima intellectiva est forma corporis humani, quod formatur per virtutem seminis. Ergo et anima intellectiva per virtutem seminis causatur.

Argumentum 4

Praeterea, homo generat sibi simile secundum speciem.

Sed species humana constituitur per animam rationalem.

Ergo anima rationalis est a generante.

Argumentum 5

Praeterea, inconveniens est dicere quod deus cooperetur peccantibus. Sed si animae rationales crearentur a deo, deus interdum cooperaretur adulteris, de quorum illicito coitu proles interdum generatur.

Non ergo animae rationales creantur a deo.

Sed Contra

Sed contra est quod dicitur in libro de eccles. Dogmat., quod animae rationales non seminantur per coitum.

Corpus

Respondeo dicendum quod impossibile est virtutem activam quae est in materia, extendere suam actionem ad producendum immaterialem effectum. Manifestum est autem quod principium intellectivum in homine est principium transcendens materiam, habet enim operationem in qua non communicat corpus. Et ideo impossibile est quod virtus quae est in semine, sit productiva intellectivi principii. Similiter etiam quia virtus quae est in semine agit in virtute animae generantis, secundum quod anima generantis est actus corporis, utens ipso corpore in sua operatione. In operatione autem intellectus non communicat corpus.

Unde virtus intellectivi principii, prout intellectivum est, non potest ad semen pervenire.

Et ideo philosophus, in libro de generat. Animal., dicit, relinquitur intellectus solus de foris advenire.

Similiter etiam anima intellectiva, cum habeat operationem sine corpore, est subsistens, ut supra habitum est, et ita sibi debetur esse et fieri. Et cum sit immaterialis substantia, non potest causari per generationem, sed solum per creationem a deo.

Ponere ergo animam intellectivam a generante causari, nihil est aliud quam ponere eam non subsistentem; et per consequens corrumpi eam cum corpore. Et ideo haereticum est dicere quod anima intellectiva traducatur cum semine.

Ad 1

Ad primum ergo dicendum quod in auctoritate illa ponitur per synecdochen pars pro toto, idest anima pro toto homine.

Ad 2

Ad secundum dicendum quod aliqui dixerunt quod operationes vitae quae apparent in embryone, non sunt ab anima eius, sed ab anima matris; vel a virtute formativa quae est in semine.

Quorum utrumque falsum est, opera enim vitae non possunt esse a principio extrinseco, sicut sentire, nutriri et augeri. Et ideo dicendum est quod anima praeexistit in embryone a principio quidem nutritiva, postmodum autem sensitiva, et tandem intellectiva. Dicunt ergo quidam quod supra animam vegetabilem quae primo inerat, supervenit alia anima, quae est sensitiva; et supra illam iterum alia, quae est intellectiva. Et sic sunt in homine tres animae, quarum una est in potentia ad aliam.

Quod supra improbatum est.

Et ideo alii dicunt quod illa eadem anima quae primo fuit vegetativa tantum, postmodum, per actionem virtutis quae est in semine, perducitur ad hoc quod fiat etiam sensitiva; et tandem perducitur ad hoc ut ipsa eadem fiat intellectiva, non quidem per virtutem activam seminis, sed per virtutem superioris agentis, scilicet dei deforis illustrantis.

Et propter hoc dicit philosophus quod intellectus venit ab extrinseco.

Sed hoc stare non potest. Primo quidem, quia nulla forma substantialis recipit magis et minus; sed superadditio maioris perfectionis facit aliam speciem, sicut additio unitatis facit aliam speciem in numeris. Non est autem possibile ut una et eadem forma numero sit diversarum specierum. Secundo, quia sequeretur quod generatio animalis esset motus continuus, paulatim procedens de imperfecto ad perfectum; sicut accidit in alteratione. Tertio, quia sequeretur quod generatio hominis aut animalis non sit generatio simpliciter, quia subiectum eius esset ens actu. Si enim a principio in materia prolis est anima vegetabilis, et postmodum usque ad perfectum paulatim perducitur; erit semper additio perfectionis sequentis sine corruptione perfectionis praecedentis. Quod est contra rationem generationis simpliciter. Quarto, quia aut id quod causatur ex actione dei, est aliquid subsistens, et ita oportet quod sit aliud per essentiam a forma praeexistente, quae non erat subsistens; et sic redibit opinio ponentium plures animas in corpore. Aut non est aliquid subsistens, sed quaedam perfectio animae praeexistentis, et sic ex necessitate sequitur quod anima intellectiva corrumpatur, corrupto corpore; quod est impossibile.

Est autem et alius modus dicendi, secundum eos qui ponunt unum intellectum in omnibus.

Quod supra improbatum est.

Et ideo dicendum est quod, cum generatio unius semper sit corruptio alterius, necesse est dicere quod tam in homine quam in animalibus aliis, quando perfectior forma advenit, fit corruptio prioris, ita tamen quod sequens forma habet quidquid habebat prima, et adhuc amplius. Et sic per multas generationes et corruptiones pervenitur ad ultimam formam substantialem, tam in homine quam in aliis animalibus. Et hoc ad sensum apparet in animalibus ex putrefactione generatis. Sic igitur dicendum est quod anima intellectiva creatur a deo in fine generationis humanae, quae simul est et sensitiva et nutritiva, corruptis formis praeexistentibus.

Ad 3

Ad tertium dicendum quod ratio illa locum habet in diversis agentibus non ordinatis ad invicem. Sed si sint multa agentia ordinata, nihil prohibet virtutem superioris agentis pertingere ad ultimam formam; virtutes autem inferiorum agentium pertingere solum ad aliquam materiae dispositionem; sicut virtus seminis disponit materiam, virtus autem animae dat formam, in generatione animalis.

Manifestum est autem ex praemissis quod tota natura corporalis agit ut instrumentum spiritualis virtutis; et praecipue dei. Et ideo nihil prohibet quin formatio corporis sit ab aliqua virtute corporali, anima autem intellectiva sit a solo deo.

Ad 4

Ad quartum dicendum quod homo generat sibi simile, inquantum per virtutem seminis eius disponitur materia ad susceptionem talis formae.

Ad 5

Ad quintum dicendum quod in actione adulterorum, illud quod est naturae, bonum est, et huic cooperatur deus. Quod vero est inordinatae voluptatis, malum est, et huic deus non cooperatur.