Thomas Aquinas, Summa Theologiae

Objection 1: It would seem that it is not proper to the rational nature to be adopted. For God is not said to be the Father of the rational creature, save by adoption. But God is called the Father even of the irrational creature, according to Job 38:28: "Who is father of the rain? Or who begot the drops of dew?" Therefore it is not proper to the rational creature to be adopted.

Objection 2: Further, by reason of adoption some are called sons of God. But to be sons of God seems to be properly attributed by the Scriptures to the angels; according to Job 1:6: "On a certain day when the sons of God came to stand before the Lord." Therefore it is not proper to the rational creature to be adopted.

Objection 3: Further, whatever is proper to a nature, belongs to all that have that nature: just as risibility belongs to all men. But to be adopted does not belong to every rational nature. Therefore it is not proper to human nature.

On the contrary, Adopted sons are the "heirs of God," as is stated Rm. 8:17. But such an inheritance belongs to none but the rational nature. Therefore it is proper to the rational nature to be adopted.

I answer that, As stated above (Article 2, ad 3), the sonship of adoption is a certain likeness of natural sonship. Now the Son of God proceeds naturally from the Father as the Intellectual Word, in oneness of nature with the Father. To this Word, therefore, something may be likened in three ways. First, on the part of the form but not on the part of its intelligibility: thus the form of a house already built is like the mental word of the builder in its specific form, but not in intelligibility, because the material form of a house is not intelligible, as it was in the mind of the builder. In this way every creature is like the Eternal Word; since it was made through the Word. Secondly, the creature is likened to the Word, not only as to its form, but also as to its intelligibility: thus the knowledge which is begotten in the disciple's mind is likened to the word in the mind of the master. In this way the rational creature, even in its nature, is likened to the Word of God. Thirdly, a creature is likened to the Eternal Word, as to the oneness of the Word with the Father, which is by reason of grace and charity: wherefore our Lord prays (Jn. 17:21,22): "That they may be one in Us . . . as We also are one." And this likeness perfects the adoption: for to those who are thus like Him the eternal inheritance is due. It is therefore clear that to be adopted belongs to the rational creature alone: not indeed to all, but only to those who have charity; which is "poured forth in our hearts by the Holy Ghost" (Rm. 5:5); for which reason (Rm. 8:15) the Holy Ghost is called "the Spirit of adoption of sons."

Reply to Objection 1: God is called the Father of the irrational creature, not properly speaking, by reason of adoption, but by reason of creation; according to the first-mentioned participation of likeness.

Reply to Objection 2: Angels are called sons of God by adoptive sonship, not that it belongs to them first; but because they were the first to receive the adoption of sons.

Reply to Objection 3: Adoption is a property resulting not from nature, but from grace, of which the rational nature is capable. Therefore it need not belong to every rational nature: but every rational creature must needs be capable of adoption.

Articulus 3

Argumentum 1

Ad tertium sic proceditur. Videtur quod adoptari non sit proprium rationalis creaturae. Non enim deus pater creaturae rationalis dicitur nisi per adoptionem. Dicitur autem pater creaturae etiam irrationalis, secundum illud iob XXXVIII, quis est pluviae pater? aut quis genuit stillas roris? ergo adoptari non est proprium rationalis naturae.

Argumentum 2

Praeterea, per adoptionem dicuntur aliqui filii dei. Sed esse filios dei in Scriptura proprie videtur attribui Angelis, secundum illud iob I, quadam autem die, cum assisterent filii dei coram domino.

Ergo non est proprium rationalis creaturae adoptari.

Argumentum 3

Praeterea, quod est proprium alicui naturae, convenit omnibus habentibus naturam illam, sicut risibile convenit omnibus hominibus. Sed adoptari non convenit omni rationali naturae.

Ergo adoptari non est proprium rationalis naturae.

Sed Contra

Sed contra est quod filii adoptati sunt heredes dei, ut patet Rom. VIII.

Sed talis hereditas convenit soli creaturae rationali. Ergo proprium rationalis creaturae est adoptari.

Corpus

Respondeo dicendum quod, sicut dictum est, filiatio adoptionis est quaedam similitudo filiationis naturalis. Filius autem dei naturaliter procedit a patre ut verbum intellectuale, unum cum ipso patre existens. Huic ergo verbo tripliciter potest aliquid assimilari. Uno quidem modo, secundum rationem formae, non autem secundum intellectualitatem ipsius, sicut forma domus exterius constitutae assimilatur verbo mentali artificis secundum speciem formae, non autem secundum intelligibilitatem, quia forma domus in materia non est intelligibilis, sicut erat in mente artificis.

Et hoc modo verbo aeterno assimilatur quaelibet creatura, cum sit facta per verbum. Secundo assimilatur creatura verbo, non solum quantum ad rationem formae, sed etiam quantum ad intellectualitatem ipsius, sicut scientia quae fit in mente discipuli, assimilatur verbo quod est in mente magistri. Et hoc modo creatura rationalis, etiam secundum suam naturam, assimilatur verbo dei. Tertio modo, assimilatur creatura verbo aeterno secundum unitatem quam habet ad patrem, quod quidem fit per gratiam et caritatem, unde dominus orat, Ioan. XVII, sint unum in nobis, sicut et nos unum sumus.

Et talis assimilatio perficit rationem adoptionis, quia sic assimilatis debetur hereditas aeterna. Unde manifestum est quod adoptari convenit soli creaturae rationali, non tamen omni, sed solum habenti caritatem. Quae est diffusa in cordibus nostris per spiritum sanctum, ut dicitur Rom. V. Et ideo, Rom. VIII, spiritus sanctus dicitur spiritus adoptionis filiorum.

Ad 1

Ad primum ergo dicendum quod deus dicitur pater creaturae irrationalis, non proprie per adoptionem, sed per creationem, secundum primam participationem similitudinis.

Ad 2

Ad secundum dicendum quod Angeli dicuntur filii dei filiatione adoptionis, non quia ipsis primo conveniat, sed quia ipsi primo adoptionem filiorum receperunt.

Ad 3

Ad tertium dicendum quod adoptio non est proprium consequens naturam, sed consequens gratiam, cuius natura rationalis est capax.

Et ideo non oportet quod omni rationali creaturae conveniat, sed quod omnis rationalis creatura sit capax adoptionis.