1 Objection 1: It would seem that the Son is not equal to the Father in power. For it is said Jn. 5, 19): The Son cannot do anything of Himself but what He seeth the Father doing. But the Father can act of Himself. Therefore the Father's power is greater than the Son's.
1 Ad sextum sic proceditur. Videtur quod filius non sit aequalis patri secundum potentiam. Dicitur enim Ioan. V, non potest filius a se facere quidquam, nisi quod viderit patrem facientem. Pater autem a se potest facere. Ergo pater maior est filio secundum potentiam.
2 Objection 2: Further, greater is the power of him who commands and teaches than of him who obeys and hears. But the Father commands the Son according to Jn. 14, 31: As the Father gave Me commandment so do I. The Father also teaches the Son: The Father loveth the Son, and showeth Him all things that Himself doth Jn. 5, 20). Also, the Son hears: As I hear, so I judge Jn. 5, 30). Therefore the Father has greater power than the Son.
2 Praeterea, maior est potentia eius qui praecipit et docet, quam eius qui obedit et audit. Sed pater mandat filio, secundum illud Ioan. XIV, sicut mandatum dedit mihi pater, sic facio. Pater etiam docet filium, secundum illud Ioan. V, pater diligit filium, et omnia demonstrat ei quae ipse facit. Similiter et filius audit, secundum illud Ioan. V, sicut audio, iudico. Ergo pater est maioris potentiae quam filius.
3 Objection 3: Further, it belongs to the Father's omnipotence to be able to beget a Son equal to Himself. For Augustine says Contra Maxim. iii, 7), Were He unable to beget one equal to Himself, where would be the omnipotence of God the Father? But the Son cannot beget a Son, as proved above Question 41, Article 6). Therefore the Son cannot do all that belongs to the Father's omnipotence; and hence He is not equal to Him power.
3 Praeterea, ad omnipotentiam patris pertinet quod possit filium generare sibi aequalem, dicit enim Augustinus, in libro contra Maximin., si non potuit generare sibi aequalem, ubi est omnipotentia Dei patris? Sed filius non potest generare filium, ut supra ostensum est. Non ergo quidquid pertinet ad omnipotentiam patris, potest filius. Et ita non est ei in potestate aequalis.
4 On the contrary, It is said Jn. 5, 19): Whatsoever things the Father doth, these the Son also doth in like manner.
4 Sed contra est quod dicitur Ioan. V, quaecumque pater facit, haec et filius similiter facit.
5 I answer that, The Son is necessarily equal to the Father in power. Power of action is a consequence of perfection in nature. In creatures, for instance, we see that the more perfect the nature, the greater power is there for action. Now it was shown above Article 4) that the very notion of the divine paternity and filiation requires that the Son should be the Father's equal in greatness, that is, in perfection of nature. Hence it follows that the Son is equal to the Father in power; and the same applies to the Holy Ghost in relation to both.
5 Respondeo dicendum quod necesse est dicere quod filius est aequalis patri in potestate. Potentia enim agendi consequitur perfectionem naturae, videmus enim in creaturis quod quanto aliquid habet perfectiorem naturam, tanto est maioris virtutis in agendo. Ostensum est autem supra quod ipsa ratio divinae paternitatis et filiationis exigit quod filius sit aequalis patri in magnitudine, idest in perfectione naturae. Unde relinquitur quod filius sit aequalis patri in potestate. Et eadem ratio est de spiritu sancto respectu utriusque.
6 Reply to Objection 1: The words, the Son cannot of Himself do anything, do not withdraw from the Son any power possessed by the Father, since it is immediately added, Whatsoever things the Father doth, the Son doth in like manner; but their meaning is to show that the Son derives His power from the Father, of Whom He receives His nature. Hence, Hilary says De Trin. ix), The unity of the divine nature implies that the Son so acts of Himself per se), that He does not act by Himself a se).
6 Ad primum ergo dicendum quod in hoc quod dicitur quod filius non potest a se facere quidquam, non subtrahitur filio aliqua potestas quam habeat pater; cum statim subdatur quod quaecumque pater facit, filius similiter facit. Sed ostenditur quod filius habet potestatem a patre, a quo habet naturam. Unde dicit Hilarius, IX de Trin., naturae divinae haec unitas est, ut ita per se agat filius, quod non a se agat.
7 Reply to Objection 2: The Father's showing and the Son's hearing are to be taken in the sense that the Father communicates knowledge to the Son, as He communicates His essence. The command of the Father can be explained in the same sense, as giving Him from eternity knowledge and will to act, by begetting Him. Or, better still, this may be referred to Christ in His human nature.
7 Ad secundum dicendum quod in demonstratione patris et auditione filii, non intelligitur nisi quod pater communicat scientiam filio, sicut et essentiam. Et ad idem potest referri mandatum patris, per hoc quod ab aeterno dedit ei scientiam et voluntatem agendorum, eum generando. Vel potius referendum est ad Christum secundum humanam naturam.
8 Reply to Objection 3: As the same essence is paternity in the Father, and filiation in the Son: so by the same power the Father begets, and the Son is begotten. Hence it is clear that the Son can do whatever the Father can do; yet it does not follow that the Son can beget; for to argue thus would imply transition from substance to relation, for generation signifies a divine relation. So the Son has the same omnipotence as the Father, but with another relation; the Father possessing power as giving signified when we say that He is able to beget; while the Son possesses the power of receiving, signified by saying that He can be begotten.
8 Ad tertium dicendum quod, sicut eadem essentia quae in patre est paternitas, in filio est filiatio; ita eadem est potentia qua pater generat, et qua filius generatur. Unde manifestum est quod quidquid potest pater, potest filius. Non tamen sequitur quod possit generare, sed mutatur quid in ad aliquid, nam generatio significat relationem in divinis. Habet ergo filius eandem omnipotentiam quam pater, sed cum alia relatione. Quia pater habet eam ut dans, et hoc significatur, cum dicitur quod potest generare. Filius autem habet eam ut accipiens, et hoc significatur, cum dicitur quod potest generari.