Thomas Aquinas, Summa Theologiae

Objection 1: It would seem that it does not belong to Christ as man to be Head of the Church. For the head imparts sense and motion to the members. Now spiritual sense and motion which are by grace, are not imparted to us by the Man Christ, because, as Augustine says (De Trin. i, 12; xv, 24), "not even Christ, as man, but only as God, bestows the Holy Ghost." Therefore it does not belong to Him as man to be Head of the Church.

Objection 2: Further, it is not fitting for the head to have a head. But God is the Head of Christ, as man, according to 1 Cor. 11:3, "The Head of Christ is God." Therefore Christ Himself is not a head.

Objection 3: Furthermore, the head of a man is a particular member, receiving an influx from the heart. But Christ is the universal principle of the whole Church. Therefore He is not the Head of the Church.

On the contrary, It is written (Eph. 1:22): "And He . . . hath made Him head over all the Church."

I answer that, As the whole Church is termed one mystic body from its likeness to the natural body of a man, which in divers members has divers acts, as the Apostle teaches (Rm. 12; 1 Cor. 12), so likewise Christ is called the Head of the Church from a likeness with the human head, in which we may consider three things, viz. order, perfection, and power: "Order," indeed; for the head is the first part of man, beginning from the higher part; and hence it is that every principle is usually called a head according to Ezech. 16:25: "At every head of the way, thou hast set up a sign of thy prostitution"---"Perfection," inasmuch as in the head dwell all the senses, both interior and exterior, whereas in the other members there is only touch, and hence it is said (Is. 9:15): "The aged and honorable, he is the head"---"Power," because the power and movement of the other members, together with the direction of them in their acts, is from the head, by reason of the sensitive and motive power there ruling; hence the ruler is called the head of a people, according to 1 Kgs. 15:17: "When thou wast a little one in thy own eyes, wast thou not made the head of the tribes of Israel?" Now these three things belong spiritually to Christ. First, on account of His nearness to God His grace is the highest and first, though not in time, since all have received grace on account of His grace, according to Rm. 8:29: "For whom He foreknew, He also predestinated to be made conformable to the image of His Son; that He might be the first-born amongst many brethren." Secondly, He had perfection as regards the fulness of all graces, according to Jn. 1:14, "We saw Him . . . full of grace and truth," as was shown, Question 7, Article 9. Thirdly, He has the power of bestowing grace on all the members of the Church, according to Jn. 1:16: "Of His fulness we have all received." And thus it is plain that Christ is fittingly called the Head of the Church.

Reply to Objection 1: To give grace or the Holy Ghost belongs to Christ as He is God, authoritatively; but instrumentally it belongs also to Him as man, inasmuch as His manhood is the instrument of His Godhead. And hence by the power of the Godhead His actions were beneficial, i.e. by causing grace in us, both meritoriously and efficiently. But Augustine denies that Christ as man gives the Holy Ghost authoritatively. Even other saints are said to give the Holy Ghost instrumentally, or ministerially, according to Gal. 3:5: "He . . . who giveth to you the Spirit."

Reply to Objection 2: In metaphorical speech we must not expect a likeness in all respects; for thus there would be not likeness but identity. Accordingly a natural head has not another head because one human body is not part of another; but a metaphorical body, i.e. an ordered multitude, is part of another multitude as the domestic multitude is part of the civil multitude; and hence the father who is head of the domestic multitude has a head above him, i.e. the civil governor. And hence there is no reason why God should not be the Head of Christ, although Christ Himself is Head of the Church.

Reply to Objection 3: The head has a manifest pre-eminence over the other exterior members; but the heart has a certain hidden influence. And hence the Holy Ghost is likened to the heart, since He invisibly quickens and unifies the Church; but Christ is likened to the Head in His visible nature in which man is set over man.

Articulus 1

Argumentum 1

Ad primum sic proceditur. Videtur quod christo, secundum quod est homo, non competat esse caput ecclesiae. Caput enim influit sensum et motum in membra. Sensus autem et motus spiritualis, qui est per gratiam, non influitur nobis a christo homine, quia, sicut dicit Augustinus, in XV de Trin., nec etiam christus, secundum quod est homo, dat spiritum sanctum, sed solum inquantum est deus.

Ergo ei, secundum quod est homo, non competit esse caput ecclesiae.

Argumentum 2

Praeterea, capitis non videtur esse aliud caput.

Sed christi, secundum quod est homo, caput est deus, secundum illud I Cor. XI, caput christi deus.

Ergo ipse christus non est caput.

Argumentum 3

Praeterea, caput in homine est quoddam particulare membrum influentiam recipiens a corde. Sed christus est universale principium totius ecclesiae. Ergo non est ecclesiae caput.

Sed Contra

Sed contra est quod dicitur Ephes. I, ipsum dedit caput super omnem ecclesiam.

Corpus

Respondeo dicendum quod, sicut tota ecclesia dicitur unum corpus mysticum per similitudinem ad naturale corpus hominis, quod secundum diversa membra habet diversos actus, ut apostolus docet, Rom. XII et I Cor. XII; ita christus dicitur caput ecclesiae secundum similitudinem humani capitis. In quo tria possumus considerare, scilicet ordinem, perfectionem et virtutem.

Ordinem, quia caput est prima pars hominis, incipiendo a superiori.

Et inde est quod omne principium consuevit vocari caput, secundum illud Ierem. II, ad omne caput viae posuisti lupanar tibi.

Perfectionem autem, quia in capite vigent omnes sensus et interiores et exteriores, cum in ceteris membris sit solus tactus.

Et inde est quod dicitur Isaiae IX, senex et honorabilis ipse est caput.

Virtutem vero, quia virtus et motus ceterorum membrorum, et gubernatio eorum in suis actibus, est a capite, propter vim sensitivam et motivam ibi dominantem. Unde et rector dicitur caput populi, secundum illud I Reg. XV, cum esses parvulus in oculis tuis, caput in tribubus Israel factus es.

Haec autem tria competunt christo spiritualiter. Primo enim, secundum propinquitatem ad deum gratia eius altior et prior est, etsi non tempore, quia omnes alii acceperunt gratiam per respectum ad gratiam ipsius, secundum illud Rom. VIII, quos praescivit, hos et praedestinavit conformes fieri imaginis filii sui, ut sit ipse primogenitus in multis fratribus.

Secundo vero, perfectionem habet quantum ad plenitudinem omnium gratiarum, secundum illud Ioan. I, vidimus eum plenum gratiae et veritatis, ut supra ostensum est.

Tertio, virtutem habuit influendi gratiam in omnia membra ecclesiae, secundum illud Ioan. I, de plenitudine eius omnes accepimus.

Et sic patet quod convenienter dicitur christus caput ecclesiae.

Ad 1

Ad primum ergo dicendum quod dare gratiam aut spiritum sanctum convenit christo secundum quod deus, auctoritative, sed instrumentaliter ei convenit secundum quod est homo, inquantum scilicet eius humanitas fuit instrumentum divinitatis eius.

Et ita actiones ipsius ex virtute divinitatis fuerunt nobis salutiferae, utpote gratiam in nobis causantes, et per meritum et per efficientiam quandam. Augustinus autem negat christum, secundum quod est homo, dare spiritum sanctum per auctoritatem.

Instrumentaliter autem, sive ministerialiter, etiam alii sancti dicuntur dare spiritum sanctum, secundum illud Galat. III, qui tribuit vobis spiritum sanctum, etc..

Ad 2

Ad secundum dicendum quod in metaphoricis locutionibus non oportet attendi similitudinem quantum ad omnia, sic enim non esset similitudo, sed rei veritas. Capitis igitur naturalis non est caput aliud, quia corpus humanum non est pars alterius corporis.

Sed corpus similitudinarie dictum, idest aliqua multitudo ordinata, est pars alterius multitudinis, sicut multitudo domestica est pars multitudinis civilis. Et ideo paterfamilias, qui est caput multitudinis domesticae, habet super se caput rectorem civitatis. Et per hunc modum nihil prohibet caput christi esse deum, cum tamen ipse sit caput ecclesiae.

Ad 3

Ad tertium dicendum quod caput habet manifestam eminentiam respectu exteriorum membrorum, sed cor habet quandam influentiam occultam. Et ideo cordi comparatur spiritus sanctus, qui invisibiliter ecclesiam vivificat et unit, capiti comparatur christus, secundum visibilem naturam, qua homo hominibus praefertur