Aquinas’s Case for Apostolic Succession (and the Papacy)

 In the fourth book of his Summa contra Gentiles (SCG), St. Thomas Aquinas considers the sacraments of the Church as extensions and instruments of Christ’s incarnation and redemptive acts. The sacraments are the means by which we participate in Christ’s incarnation, passion, death, resurrection:

“Since . . . the death of Christ is as a universal cause of human salvation; but it is necessary that a universal cause be applied to each [particular] effect: [so] it was necessary that certain remedies be supplied to men through which the benefit of the death of Christ might somehow be conjoined to them. Now the sacraments of the Church are said to be [remedies] of this sort” (“Quia vero, sicut iam dictum est, mors Christi est quasi universalis causa humanae salutis; universalem autem causam oportet applicari ad unumquemque effectum: necessarium fuit exhiberi hominibus quaedam remedia per quae eis beneficium mortis Christi quodammodo coniungeretur. Huiusmodi autem esse dicuntur Ecclesiae sacramenta,” SCG IV.56).

Insofar as the sacraments are extensions and instruments of Christ’s saving work, their “institution and power has its source from Christ” (“Sacramentorum enim institutio et virtus a Christo initium habet,” SCG IV.74). But at the ascension, the Lord withdrew his visible, bodily presence from the Church; so, for the actual dispensation of the sacraments to the Church on earth, “it was necessary that he institute others ministering to him, who might dispense the sacraments to the faithful” (“Quia igitur Christus corporalem sui praesentiam erat Ecclesiae subtracturus, necessarium fuit ut alios institueret sibi ministros, qui sacramenta fidelibus dispensarent,” ibid.). These ministers share in Christ’s own power and authority as his instruments in extending the effects of his own salvific works to mankind.

The “firstfruits” of these ministers were, of course, the apostles. So St. Paul refers to his own apostolic ministry as follows: “This is how one should regard us, as servants of Christ and stewards of the mysteries of God” (1 Corinthians 4:1, referenced in SCG IV.74). To this end, we see Christ committing the Eucharist to the apostles: “Do this in remembrance of me” (Luke 22:19, referenced in SCG IV.74). We see him giving the apostles the very power of remitting sins: “If you forgive the sins of any, they are forgiven” (John 20:23, referenced in ibid.). And he gave to them also “the office of teaching and baptizing,” saying “Go therefore and make disciples of all nations, baptizing them” (Matthew 28:19, referenced in ibid.). So, very clearly, Christ gave to the apostles the power and authority to teach revealed truth, retain and remit sins, and dispense sacraments, among other prerogatives.

The crucial question then becomes: is this apostolic power and authority limited to the actual apostles themselves? St. Thomas gives the following case that it is not and cannot be:

“Now it is not to be said that this power is given to the disciples of Christ in such a way that it could not be delivered through them to others: for it was given to them for the edification of the Church, according to the statement of the Apostle. Therefore it is necessary that this power be perpetuated for as long as it is necessary to edify the Church. But such is necessary after the death of the disciples of Christ even to the end of the age. Thus therefore spiritual power was given to the disciples of Christ such that through them it might be delivered to others” (“Non est autem dicendum quod potestas huiusmodi sic data sit Christi discipulis quod per eos ad alios derivanda non esset: data est enim eis ad Ecclesiae aedificationem, secundum apostoli dictum. Tandiu igitur oportet hanc potestatem perpetuari, quandiu necesse est aedificari Ecclesiam. Hoc autem necesse est post mortem discipulorum Christi usque ad saeculi finem. Sic igitur data fuit discipulis Christi spiritualis potestas ut per eos deveniret ad alios,” SCG IV.74).

We can summarize St. Thomas’s entire case as follows: the truths of the Faith and the grace of the sacraments are the extension of Christ’s own incarnation, teaching, passion, death, and resurrection, through which we ourselves are enabled to participate in those very mysteries. In order that those mysteries be made available to us after Christ’s ascension, Christ established the office of the apostles, to whom he gave a share in his own power and authority to teach the Faith and administer the sacraments. The power of this apostolic office is ordered to the fulfillment of its divine function. But that function does not cease with the death of the apostles: indeed, it is a function absolutely necessary and essential to the life and preservation of the whole Church. Since, therefore, the function is essential to and continues along with the whole life of the Church, the power ordered to carrying out that function must be essential to and continue along with the whole life of the Church as well. Hence, the power and authority given by Christ to the apostles to teach revealed truth, retain and remit sins, administer sacraments, etc. must be able to be passed from the apostles themselves to others who carry out their same mission and function. This is precisely what the doctrine of apostolic succession teaches.

St. Thomas then continues this very same case and applies it to the Papacy. He gives four independent arguments for a single, visible “head” and “shepherd” of the universal Church. I will share what I take to be the three strongest here. First, an argument from the unity of the universal Church:

“Now it is manifest that although the people are divided through diverse dioceses and cities, yet, as there is one Church, thus it is necessary that there be one Christian people. As therefore in one specific people of one church there is required one bishop, who is the head of the whole people; so in the whole Christian people there is required that there is one head of the whole Church” (“Manifestum est autem quod quamvis populi distinguantur per diversas dioeceses et civitates, tamen, sicut est una Ecclesia, ita oportet esse unum populum Christianum. Sicut igitur in uno speciali populo unius Ecclesiae requiritur unus episcopus, qui sit totius populi caput; ita in toto populo Christiano requiritur quod unus sit totius Ecclesiae caput” SCG IV.76). In short: just as each particular, local church has one head/shepherd, so the universal Church needs one head/shepherd.

Second, from unity of faith. The unity of the Church requires a unity in faith. But about matters of faith there are many different questions and opinions, which would divide the Church unless there were a single, ultimate arbiter whose judgement could resolve disputes about the faith. Therefore, “for conserving the unity of the Church there is demanded that there is one who presides over the whole Church. But it is manifest that Christ does not fail the Church in necessities, whom he loves, and for whom he shed his own blood: since even of the synagogue it is said through the Lord: “What more was there to do for my vineyard, that I have not done in it?” [Isaiah 5:4]. Therefore it is not to be doubted that from the ordination of Christ there is one who presides over the whole Church” (ibid.).

Third, from the likeness of the Church Militant (Church on earth) to the Church Triumphant (Church in heaven). The Church Militant is an image of the Church Triumphant. “Hence John in the Apocalypse “saw the holy city, new Jerusalem, coming down out of heaven” [Revelation 21:2], and the command to Moses was that he should make all things “after the pattern form the, which is being shown you on the mountain” [Exodus 25:40]. But in the Church Triumphant one presides, who also presides in the whole universe, namely God: for it said “they shall be his people, and God himself will be with them” [Revelation 21:3]. Therefore also in the Church Militant there is one who presides over the universal [whole]” (“unde et Ioannes in Apocalypsi, vidit Ierusalem descendentem de caelo; et Moysi dictum est quod faceret omnia secundum exemplar ei in monte monstratum. In triumphanti autem Ecclesia unus praesidet, qui etiam praesidet in toto universo, scilicet Deus: dicitur enim Apoc. 21:3: ipsi populus eius erunt, et ipse cum eis erit eorum Deus. Ergo et in Ecclesia militante unus est qui praesidet universis” ibid.).

Now, one might object that the “one who presides” over the universal Church is none other than Christ himself. St. Thomas anticipates this objection and in response applies the same line of thinking regarding apostolic succession to the present case. I quote at length:

“If, however, someone should say that the one head and one shepherd is Christ, who is the one bridegroom of the one Church: he does not respond sufficiently. For it is manifest that Christ himself perfects all the ecclesiastical sacraments: for it is he who baptizes; he who remits sins; he is the true priest, who offered himself on the altar of the cross, and by whose power his own body is offered daily on the altar: and yet, since he was about to be not bodily present with all the faithful, he chose ministers, through whom he might dispense the aforesaid things to the faithful . . . Therefore by the same reason, since his bodily presence to the Church was about to be withdrawn, it was necessary that he commit to someone who would bear in his place the care of the universal Church. Hence it is that he said to Peter before the ascension: “Feed my sheep” [John 21:17]; and before the passion: “and when you have turned again, strengthen your brethren” [Luke 22:32]; and to him alone he promised: “I will give you the keys of the kingdom of heaven” [Matthew 16:19]; so that he might show that the power of the keys was to be delivered through him to others, for conserving the unity of the Church. But it cannot be said, that even if he gave this dignity to Peter, yet it is not delivered to others. For it is manifest that Christ thus instituted the Church that it would endure to the end of the age . . . Therefore it is manifest that he thus constituted those who were then in ministry, that their power would be delivered to successors, for the utility of the Church, even to the end of the age: especially since he himself says: “Behold, I am with you always, to the close of the age” [Matthew 28:20]. Through this is excluded the presumptuous error of some, who strive to remove themselves from obedience and subjection to Peter, not recognizing his successor the Roman pontiff the shepherd of the universal Church” (“Si quis autem dicat quod unum caput et unus pastor est Christus, qui est unus unius Ecclesiae sponsus: non sufficienter respondet. Manifestum est enim quod omnia ecclesiastica sacramenta ipse Christus perficit: ipse enim est qui baptizat; ipse qui peccata remittit; ipse est verus sacerdos, qui se obtulit in ara crucis, et cuius virtute corpus eius in altari quotidie consecratur: et tamen, quia corporaliter non cum omnibus fidelibus praesentialiter erat futurus, elegit ministros, per quos praedicta fidelibus dispensaret, ut supra dictum est. Eadem igitur ratione, quia praesentiam corporalem erat Ecclesiae subtracturus, oportuit ut alicui committeret qui loco sui universalis Ecclesiae gereret curam. Hinc est quod Petro dixit ante ascensionem: pasce oves meas, Ioan. ult.; et ante passionem: tu iterum conversus, confirma fratres tuos Lucae 22:32; et ei soli promisit: tibi dabo claves regni caelorum; ut ostenderetur potestas clavium per eum ad alios derivanda, ad conservandam Ecclesiae unitatem. Non potest autem dici quod, etsi Petro hanc dignitatem dederit, tamen ad alios non derivatur. Manifestum est enim quod Christus Ecclesiam sic instituit ut esset usque ad finem saeculi duratura . . . Manifestum est igitur quod ita illos qui tunc erant in ministerio constituit, ut eorum potestas derivaretur ad posteros, pro utilitate Ecclesiae, usque ad finem saeculi: praesertim cum ipse dicat, Matth. ult.: ecce, ego vobiscum sum usque ad consummationem saeculi. Per hoc autem excluditur quorundam praesumptuosus error, qui se subducere nituntur ab obedientia et subiectione Petri, successorem eius Romanum pontificem universalis Ecclesiae pastorem non recognoscentes,” SCG IV. 76).

The argument, once again, is from necessity of the end, or the final cause. Christ wills for the Church to have a visible unity, and, in order to achieve such unity, it is necessary that the Church have a visible head and shepherd. While Christ was on earth, he himself was the visible head and shepherd; but since he was to withdraw his visible presence, he gave the role to Peter among the apostles. Yet again: Peter was to die, and if his office was not to be passed on to another, the Church would be without a visible head and shepherd. Hence, it must be the case that Peter’s office as visible head and shepherd of the universal Church be passed on — which it has, in the Roman Pontiff.

The entire above case can, in a sense, be seen as an extended contemplation of the words of the Lord: “I am with you always.” If Christ is always with us, but is not with us visibly, he must have supplied means by which we might participate in his presence, his life, his grace, by which his own life and office might be “made present” to us here. Hence he appointed ministers to share in his office, which can be passed from them to successors, so that the whole Church for all of time might continue to share in his divine goods. It is precisely in these ministers, in the truth they teach, the grace of the sacraments they administer, and the headship/shepherdship they occupy, that Christ is with us always to the end of the age.