Thomas Aquinas, Summa Theologiae

Objection 1: It would seem that no procession in God can be called generation. For generation is change from non-existence to existence, and is opposed to corruption; while matter is the subject of both. Nothing of all this belongs to God. Therefore generation cannot exist in God.

Objection 2: Further, procession exists in God, according to an intelligible mode, as above explained (Article 1). But such a process is not called generation in us; therefore neither is it to be so called in God.

Objection 3: Further, anything that is generated derives existence from its generator. Therefore such existence is a derived existence. But no derived existence can be a self-subsistence. Therefore, since the divine existence is self-subsisting (Question 3, Article 4), it follows that no generated existence can be the divine existence. Therefore there is no generation in God.

On the contrary, It is said (Ps. 2:7): "This day have I begotten Thee."

I answer that, The procession of the Word in God is called generation. In proof whereof we must observe that generation has a twofold meaning: one common to everything subject to generation and corruption; in which sense generation is nothing but change from non-existence to existence. In another sense it is proper and belongs to living things; in which sense it signifies the origin of a living being from a conjoined living principle; and this is properly called birth. Not everything of that kind, however, is called begotten; but, strictly speaking, only what proceeds by way of similitude. Hence a hair has not the aspect of generation and sonship, but only that has which proceeds by way of a similitude. Nor will any likeness suffice; for a worm which is generated from animals has not the aspect of generation and sonship, although it has a generic similitude; for this kind of generation requires that there should be a procession by way of similitude in the same specific nature; as a man proceeds from a man, and a horse from a horse. So in living things, which proceed from potential to actual life, such as men and animals, generation includes both these kinds of generation. But if there is a being whose life does not proceed from potentiality to act, procession (if found in such a being) excludes entirely the first kind of generation; whereas it may have that kind of generation which belongs to living things. So in this manner the procession of the Word in God is generation; for He proceeds by way of intelligible action, which is a vital operation:---from a conjoined principle (as above described):---by way of similitude, inasmuch as the concept of the intellect is a likeness of the object conceived:---and exists in the same nature, because in God the act of understanding and His existence are the same, as shown above (Question 14, Article 4). Hence the procession of the Word in God is called generation; and the Word Himself proceeding is called the Son.

Reply to Objection 1: This objection is based on the idea of generation in the first sense, importing the issuing forth from potentiality to act; in which sense it is not found in God.

Reply to Objection 2: The act of human understanding in ourselves is not the substance itself of the intellect; hence the word which proceeds within us by intelligible operation is not of the same nature as the source whence it proceeds; so the idea of generation cannot be properly and fully applied to it. But the divine act of intelligence is the very substance itself of the one who understands (Question 14, Article 4). The Word proceeding therefore proceeds as subsisting in the same nature; and so is properly called begotten, and Son. Hence Scripture employs terms which denote generation of living things in order to signify the procession of the divine Wisdom, namely, conception and birth; as is declared in the person of the divine Wisdom, "The depths were not as yet, and I was already conceived; before the hills, I was brought forth." (Prov. 8:24). In our way of understanding we use the word "conception" in order to signify that in the word of our intellect is found the likeness of the thing understood, although there be no identity of nature.

Reply to Objection 3: Not everything derived from another has existence in another subject; otherwise we could not say that the whole substance of created being comes from God, since there is no subject that could receive the whole substance. So, then, what is generated in God receives its existence from the generator, not as though that existence were received into matter or into a subject (which would conflict with the divine self-subsistence); but when we speak of His existence as received, we mean that He Who proceeds receives divine existence from another; not, however, as if He were other from the divine nature. For in the perfection itself of the divine existence are contained both the Word intelligibly proceeding and the principle of the Word, with whatever belongs to His perfection (Question 4, Article 2).

Articulus 2

Argumentum 1

Ad secundum sic proceditur. Videtur quod processio quae est in divinis, non possit dici generatio. Generatio enim est mutatio de non esse in esse, corruptioni opposita; et utriusque subiectum est materia. Sed nihil horum competit divinis.

Ergo non potest generatio esse in divinis.

Argumentum 2

Praeterea, in deo est processio secundum modum intelligibilem, ut dictum est.

Sed in nobis talis processio non dicitur generatio. Ergo neque in deo.

Argumentum 3

Praeterea, omne genitum accipit esse a generante. Esse ergo cuiuslibet geniti est esse receptum. Sed nullum esse receptum est per se subsistens. Cum igitur esse divinum sit esse per se subsistens, ut supra probatum est, sequitur quod nullius geniti esse sit esse divinum. Non est ergo generatio in divinis.

Sed Contra

Sed contra est quod dicitur in Psalmo II, ego hodie genui te.

Corpus

Respondeo dicendum quod processio verbi in divinis dicitur generatio. Ad cuius evidentiam, sciendum est quod nomine generationis dupliciter utimur. Uno modo, communiter ad omnia generabilia et corruptibilia, et sic generatio nihil aliud est quam mutatio de non esse ad esse. Alio modo, proprie in viventibus, et sic generatio significat originem alicuius viventis a principio vivente coniuncto. Et haec proprie dicitur nativitas. Non tamen omne huiusmodi dicitur genitum, sed proprie quod procedit secundum rationem similitudinis. Unde pilus vel capillus non habet rationem geniti et filii, sed solum quod procedit secundum rationem similitudinis, non cuiuscumque, nam vermes qui generantur in animalibus, non habent rationem generationis et filiationis, licet sit similitudo secundum genus, sed requiritur ad rationem talis generationis, quod procedat secundum rationem similitudinis in natura eiusdem speciei, sicut homo procedit ab homine, et equus ab equo.

In viventibus autem quae de potentia in actum vitae procedunt, sicut sunt homines et animalia, generatio utramque generationem includit. Si autem sit aliquod vivens cuius vita non exeat de potentia in actum, processio, si qua in tali vivente invenitur, excludit omnino primam rationem generationis; sed potest habere rationem generationis quae est propria viventium. Sic igitur processio verbi in divinis habet rationem generationis.

Procedit enim per modum intelligibilis actionis, quae est operatio vitae, et a principio coniuncto, ut supra iam dictum est, et secundum rationem similitudinis, quia conceptio intellectus est similitudo rei intellectae, et in eadem natura existens, quia in deo idem est intelligere et esse, ut supra ostensum est.

Unde processio verbi in divinis dicitur generatio, et ipsum verbum procedens dicitur filius.

Ad 1

Ad primum ergo dicendum quod obiectio illa procedit de generatione secundum rationem primam, prout importat exitum de potentia in actum. Et sic non invenitur in divinis, ut supra dictum est.

Ad 2

Ad secundum dicendum quod intelligere in nobis non est ipsa substantia intellectus, unde verbum quod secundum intelligibilem operationem procedit in nobis, non est eiusdem naturae cum eo a quo procedit. Unde non proprie et complete competit sibi ratio generationis. Sed intelligere divinum est ipsa substantia intelligentis, ut supra ostensum est, unde verbum procedens procedit ut eiusdem naturae subsistens. Et propter hoc proprie dicitur genitum et filius. Unde et his quae pertinent ad generationem viventium, utitur Scriptura ad significandam processionem divinae sapientiae, scilicet conceptione et partu, dicitur enim ex persona divinae sapientiae, Proverb. VIII, nondum erant abyssi, et ego iam concepta eram; ante colles ego parturiebar.

Sed in intellectu nostro utimur nomine conceptionis, secundum quod in verbo nostri intellectus invenitur similitudo rei intellectae, licet non inveniatur naturae identitas.

Ad 3

Ad tertium dicendum quod non omne acceptum est receptum in aliquo subiecto, alioquin non posset dici quod tota substantia rei creatae sit accepta a deo, cum totius substantiae non sit aliquod subiectum receptivum. Sic igitur id quod est genitum in divinis, accipit esse a generante, non tanquam illud esse sit receptum in aliqua materia vel subiecto (quod repugnat subsistentiae divini esse); sed secundum hoc dicitur esse acceptum, inquantum procedens ab alio habet esse divinum, non quasi aliud ab esse divino existens. In ipsa enim perfectione divini esse continetur et verbum intelligibiliter procedens, et principium verbi; sicut et quaecumque ad eius perfectionem pertinent, ut supra dictum est.