In this paper, I explore a tension that arises in Saint Thomas’s account of Christ’s headship over the angels as it appears in the Summa theologiae. Relying on a philosophical principle which has come to be known as the ‘causality of the maximum’ (i.e., that the maximum in the genus is cause in that genus), Saint Thomas argues that Christ, on account of his perfection in grace, is the universal principle of grace according to his human nature.Footnote 1 This is true of Christ with respect to ‘all of those who are members of the Church, regardless of time, place, or state’.Footnote 2 This power of transmitting grace constitutes the primary aspect of Christ’s headship.Footnote 3 Notably, Saint Thomas extends Christ’s headship to include the beatified angels, who, through their ordering to the supernatural vision of God, are no less members of the Church.Footnote 4 Yet, if Christ is head of the angels according to his humanity, it also seems to follow that he is, in the same capacity, the cause of their grace, which St Thomas suggests in certain texts. In this case, the grace given to the angels in creation would ostensibly find its source in the humanity of Christ. Such a teaching, however, seems to imply a kind of supralapsarianism, according to which the Word would have become Incarnate regardless of humanity’s fall – for even before the Fall of humanity, the angels would have received grace (perhaps proleptically as the OT saints did) through the humanity of the Incarnate Word.Footnote 5
This raises at least one problem with respect to Thomas’s Christology. Saint Thomas famously held that since Scripture only speaks of the Incarnation as a remedy for the sin of humanity, it is better to say that sin is the reason for the Incarnation than to say that the Incarnation would have occurred without sin.Footnote 6 This likely accounts for a key text that seems to limit the scope of Christ’s human headship with respect to the angels. In treating Christ’s judiciary power, Thomas states that Christ is considered the cause of angelic beatitude only according to his divine nature. Besides appearing to contradict texts describing Christ’s influence over the angels, this position more fundamentally undermines the principle of the causality of the maximum, upon which St Thomas bases Christ’s universal headship. Consequently, Christ’s humanity cannot be called the universal cause of grace. On the other hand, however, if Christ as human indeed possesses the maximum of grace in the genus of grace, it would follow that he is the cause of grace and glory in all others, including the blessed angels. In this case, it would be possible to posit Christ as human as the cause of angelic grace and glory. Yet, serious modification of Thomas’s teaching on the ratio of the Incarnation would be required.
How ought we to understand the argument for Christ’s headship over the angels and, by consequence, Saint Thomas’s argument from the causality of the maximum? While a reading of Saint Thomas’s argument in Tertia pars, qq. 8–12 gives the impression that the philosophical principle of the causality of the maximum has a determinative role (i.e., carrying the force of metaphysical necessity), I will argue that Saint Thomas’s treatment of Christ’s judiciary power (in ST III, q. 59, a. 6) highlights that the principle is not so much an a priori principle – i.e., one from which Saint Thomas’s teaching on headship is deduced – but is rather an a posteriori explanation of the revealed data – i.e., the fact that the Word became flesh to save humanity from sin. Although Christ in his humanity is the source of grace for all, this is only true in the context of the economy of human redemption. In other words, Christ is primarily the head of those who are capable of being redeemed by grace after having fallen into sin; Christ’s headship extends to the angels secondarily, only inasmuch as they are players in the drama of human redemption. From this, I show how, in the realm of the mysteries of faith, Thomas is always careful to use philosophy to illuminate, never to determine, what is fundamentally revealed. In other words, even if metaphysical principles are absolute in the realm of natural reason, their force is relativized in matters pertaining to the highest mysteries of faith.Footnote 7 Here we see an important and concrete way in which philosophy is ancilla theologiae.Footnote 8
1. Saint Thomas on Christ as the universal principle of grace
It is necessary to begin with a broader consideration of Saint Thomas’s understanding of Christ’s headship. According to Saint Thomas, the grace of headship (gratia capitis) belongs to Christ as human according to the threefold reason of order, perfection, and power.Footnote 9 Order, because Christ’s soul is above all other creatures due to its nearness to the Word through the hypostatic union; perfection, because Christ’s soul enjoys the most perfect fullness of grace; and power, because it belongs to Christ to communicate or ‘flow’ (influere) grace to all of his members. The three aspects neatly correspond to the three types of grace Saint Thomas attributes to Christ: the grace of union (q. 2), singular or individual grace (q. 7),Footnote 10 and the grace of headship (q. 8).Footnote 11 In the Tertia pars of the Summa theologiae, Saint Thomas provides an account that causally links each of these three aspects: on account of the hypostatic union, whereby Christ’s soul is the nearest to the cause of grace, Christ enjoys the greatest perfection of graceFootnote 12; from this fullness or perfection of Christ’s individual grace, on account of the metaphysical principle of the ‘causality of the maximum’, Christ is the cause of grace for all others.Footnote 13 This last aspect, the power to bestow grace to others, is the grace of headship whereby Christ’s humanity is rendered the universal principle of grace ‘from whom all receive, grace upon grace’.Footnote 14
Within the broader context of thirteenth-century scholasticism, Saint Thomas’s notion of Christ’s headship marks a significant development. Unlike some of his contemporaries, notably, Alexander of Hales and Saint Bonaventure, who, on the basis of the Augustinian dictum that God alone can give grace, conceived of Christ’s human headship as, at most, a dispositive cause of grace (i.e., Christ as human disposes or prepares others to receive grace immediately from God through his human prayer, merit, etc.),Footnote 15 Saint Thomas places Christ’s humanity at the center of the redemptive economy as an instrumental, efficient cause.Footnote 16 For Thomas, Christ’s humanity does not serve merely to prepare others for an otherwise unmediated bestowal of grace immediately from God; instead, his humanity itself mediates grace as its universal principle and source. The philosophical principle of the causality of the maximum, which is essential to the fourth way to God’s existence, here bolsters Saint Thomas’s understanding of the biblical data which speaks of Christ as head of the Church and the source of grace.Footnote 17 Through the perfection of Christ’s individual grace (through his ‘fullness of grace and truth’), Christ is seen to possess the maximum of grace rendering his human nature the cause of grace in all others.
The contrast between Saint Thomas’s teaching and that of his near predecessors and contemporaries is most evident in an image that Saint Thomas borrows from the Summa Fratris Alexandri. In the Summa Fratris, the Halensist distinguishes the grace of Christ from that of others by likening it to a flame (flamma), while likening the grace of others to a coal (carbo).Footnote 18 Christ’s grace is like a flame, not only as it has light in itself but also as it is able to illuminate those around itself; the grace of others, on the other hand, is like a coal that has light for itself but does not illuminate surrounding bodies. In his Scriptum on the Sentences, Saint Thomas amends the Halensian image by adding yet another source of light, beyond the flame, which he likens to Christ’s grace. This is the light of the sun:
We see that some things have such bodily light so that they glow, as certain worms, rotten wood, and coal; some so that they illuminate others, as the light of a candle; but still others so that every illumination (omnis illuminatio) is from them, just as it is with the sun.Footnote 19
Saint Thomas goes a step beyond the Halensist by comparing Christ directly to the sun which is the source of every illumination. He concludes:
And so it is with the grace of Christ: for he has grace through which he is perfect in himself, and which flows from him to others: and [this grace] makes some of those to whom it flows co-workers (cooperatores) with God, as it says in 1 Corinthians 3:9, and it also flows from him to all, for from his fullness we all receive, John. 1:16.Footnote 20
Saint Thomas’s revision of the Halensian image of Christ’s grace highlights the notion of Christ as the universal source and principle of all grace.
Saint Thomas will put things more starkly in the De veritate, likening the relationship of Christ’s humanity to grace to the relationship of God to being: ‘And since Christ in some way (quodammodo) flows (influit) the effects of grace to all rational creatures, thus he is himself in some way the principle of all grace according to his humanity, just as God is the principle of being’.Footnote 21 Later still, in the Tertia pars of the Summa theologiae, Saint Thomas will explicitly link this argument to the causality of the maximum:
For the soul of Christ received grace in such a way that grace might somehow be transmitted from [his soul] to others. And therefore, it was necessary (oportuit) that he possess the maximum grace (maximam gratiam), just as fire, which is the cause of heat in everything that is hot, is [itself] maximally hot (maxime calidus).Footnote 22
Consequently, Christ is head of all who receive grace, ‘in every time, place, and state’.Footnote 23
Saint Thomas neatly links Christ’s power of communicating grace to his individual perfection in grace through the principle of the causality of the maximum, which is, in turn, a result of his soul’s propinquity to the Word through the hypostatic union.Footnote 24 This more-or-less straightforward causal account of Christ as the universal principle of grace is nevertheless complicated by Christ’s relationship to the angels.
2. Christ’s headship over the angels
Bolstering the authority of Pseudo-Dionysius is the ample witness of the biblical testimony regarding Christ’s headship over the angels.Footnote 25 As in his treatment of Christ’s headship over men, Saint Thomas relies on philosophical principles to illuminate our understanding of what is revealed. But what happens when a given philosophical principle appears to lead to a conclusion that contradicts revelation? Such a contradiction seems to appear in Saint Thomas’s account of Christ’s headship when compared with his account of Christ’s judiciary power. While Christ’s headship relies on the causality of the maximum (the angels, too, are recipients of grace and glory in some way through Christ), nevertheless, Saint Thomas’s account of Christ’s judiciary power seems to strongly qualify this position, insofar as Christ is only the cause of the accidental reward of the angels and not the essential reward. In other words, Christ as human is the cause of the joy that accrues to the angels on account of the redemption of humanity, but he is not the cause of their essential reward, i.e., the glory of the angels in beholding the divine essence.
The tension between the universality of Christ’s influence, on the one hand, and its restriction to the accidental reward of the angels, on the other, is surprising given the many parallels Saint Thomas’s account of Christ’s headship over the angels (III, q. 8, a. 4) has with the account of his headship over human beings. The argument for Christ’s headship over the angels is based on the same threefold characteristic of headship: order, perfection, and power. Saint Thomas writes:
Christ is the head of this entire multitude [of angels] because he is nearer to God [i.e., order] and participates more perfectly in [God’s] gifts – and [he does this] not only more than men, but even the angels [i.e., perfection]; moreover, not only do men receive from his influence [influentia] but the angels, too [i.e., power]. Wherefore the mystical body of the Church is not constituted from men alone but also from the angels.Footnote 26
Here again, we see the application of the principle of the causality of the maximum: on account of his nearness to God and the consequent perfection he derives from that proximity, Christ’s grace is the source of ‘influence’ not only for human beings but also for the angels. Notably, as Thomas’s consideration of Christ’s headship pertains primarily to his human nature, it follows that Christ’s influence over the angels is related to his human headship.
Naturally, objections arise against the notion of Christ’s headship over the angels. First, the Word assumed a human nature not an angelic nature.Footnote 27 Second, the blessed angels, inasmuch as they enjoy the vision of God as comprehensors, cannot truly be called members of the Church, which is the congregation of the faithful (i.e., those who walk by faith, viatores). The third objection argues against Christ’s headship over the angels on the grounds that the Word was made flesh to give life (vivificat) not only to souls but also to bodies, which angels lack. Thus, Christ as human cannot give life to the angels.Footnote 28
Thomas’s several replies to the objections only strengthen the sense in which Christ as human is the source of influence for the angels. To the first objection that Christ does not share in the same nature with the angels, Saint Thomas deems it sufficient to point to the similarity in genus between human beings and angels as the basis for Christ’s headship over the angels.Footnote 29 Though human beings and angels are different in species, nevertheless, they share in the genus of intellectual creatures. To the second objection, that the Church is constituted by the faithful (i.e., viatores) and therefore excludes the blessed angels, Saint Thomas highlights Christ’s status not only as viator but also as comprehensor. For Christ, ‘as possessing grace and glory most fully’, is head of all of the blessed as much as he is head of wayfarers.Footnote 30 Finally, against the third, Saint Thomas points to the proximity of Christ’s soul to God through personal union, which enables his humanity ‘to cause something not only in the spirit of men, but also in the spirit of angels’.Footnote 31 Thus far, Christ appears to be head over the angels in much the same way that he is head over men.
When we turn to Thomas’s account of Christ’s judiciary power, i.e., ‘the power to be the judge of the living and the dead’, we find many parallels to the above account.Footnote 32 Most significantly, as with Christ’s headship, Saint Thomas is concerned to attribute judiciary power not only to Christ as Word (the opinion of Chrysostom, among others) but primarily as human.Footnote 33 Thomas’s argument for judiciary power belonging to Christ as human is explicitly premised on Christ’s headship as human. Aquinas writes, ‘Christ, in his human nature, too, is head of the whole Church and […] God subjected all things under his feet. Wherefore, to have judiciary power also pertains to him according to his human nature’.Footnote 34
On the surface, Saint Thomas’s account of Christ’s judiciary power over the angels is relatively straightforward. That Christ as human possesses judiciary power over the angels has a foundation not only in the biblical testimony (e.g., 1 Cor 6:3, quoted in the sed contra)Footnote 35 but also in the very logic of Saint Thomas’s teaching on Christ’s headship. If Christ’s headship extends to the angels, then it seems to follow that Christ’s judiciary power likewise extends to the angels. And this is just what Saint Thomas says: Christ has judiciary power over the angels because of his nearness to the Godhead; as a result, his soul is filled with ‘the truth of the Word of God’,Footnote 36 and, as Dionysius the Areopagite states in the Celestial Hierarchy, Christ illuminates even the angels.Footnote 37
There is, however, at least one fairly obvious reason as to why this might pose a problem. It makes little sense for Christ in his human nature to stand in judgment over the angels who have already been judged at the beginning of the world.Footnote 38 Does Christ in his human nature judge the angels at the beginning of the world? As Saint Thomas proceeds in his response, one detects a creeping ambivalence not evident in Saint Thomas’s earlier remarks. The angels are subject to the judgment of Christ, he tells us, ‘on account of those things they do for men (ratione eorum quae circa homines operantur), of whom Christ is, in a special way, the head’.Footnote 39 Notably, Christ’s judiciary power over the angels is here described as arising only indirectly, inasmuch as the angels act for and around human beings of whom Christ is head. In other words, it is primarily because of Christ’s headship of human beings that he can be called the judge of the angels.Footnote 40
As stated above, Saint Thomas here specifies that Christ’s judgment extends to the angels only with respect to their accidental reward – i.e., the joy they have from the salvation of humans.Footnote 41 But what of the essential reward of the good angels (i.e., eternal beatitude)? It is helpful to remind ourselves of the role of Christ’s humanity in human beatitude. In the case of humans, Saint Thomas posits beatific knowledge in Christ’s soul from the very moment of his conception inasmuch as his humanity is the very instrument by which others are brought to the beatific vision as from potency to act – ‘for the cause must always be greater than the effect’.Footnote 42 Here, too, Thomas argues for Christ’s beatific knowledge on the grounds of the causality of the maximum.Footnote 43 Yet, in the case of the angels, Saint Thomas tells us that this is not done by Christ as human ‘but as he is the Word of God, from the beginning of the world’.Footnote 44 Even if Christ’s human headship extends ‘over those who are members of the Church in every time, place, and state’,Footnote 45 it nevertheless does not appear to extend as far back to the beatitude of the angels.
Saint Thomas’s resolution to the above objection raises an important question about the causality of the maximum, which is arguably the central principle at work in his understanding of Christ’s headship. If Christ’s headship is contingent upon his perfect possession of grace and glory, then it appears that he ought to be the cause of grace and glory for all creatures. Moreover, since time is not an impediment (as we see with those members of the Church in the old covenant),Footnote 46 it seems unclear why Christ’s judiciary power should not extend all the way to the angels at the beginning of the world. But if Christ’s humanity is the universal cause of grace, it appears that the Incarnation is not, in fact, contingent upon the fall of humanity but would have been necessary for any and every communication of grace and glory to creatures.
If this last option is repugnant to Saint Thomas’s understanding of the motive of the Incarnation, how ought we understand what is going on here?
3. Conclusion: Towards a solution
In speaking of Saint Thomas’s doctrine of the non-overflow of the enjoyment of beatitude from the higher to the lower powers, Jean-Pierre Torrell makes an interesting comment about what is ‘very clearly’ Saint Thomas’s theological method:
[E]ven if the entire logic of his thought moves in a single direction, [Saint Thomas] is capable of halting it the moment he encounters a single datum that contradicts the coherence of this development. We should not be surprised at this for his method is irreproachable: the merest fact trumps every argument.Footnote 47
Does Torrell’s account accurately describe the theological method at work in Thomas’s treatment of Christ’s headship over the angels? That is, does the ‘fact’ of the motive of the Incarnation as human sin,Footnote 48 finally trump Saint Thomas’s argument based on the principle of the causality of the maximum? If so, the principle of the causality of the maximum can only ever be understood as an a posteriori account of what is revealed. Further, the principle (as with other aspects of the Incarnation that seem finally to be contingent upon the immediate will of God) is ultimately only as necessary as the Incarnation itself – which is to say, the arguments premised upon them are arguments ex convenientia, which, to be sure, carry a sense of necessity but an ambivalent one at that. Conversely, it seems that for Saint Thomas, a priori arguments based on philosophical principles cannot be carried through to their conclusions in a rigorously logical manner but always with an eye to what is more fundamental, namely, revelation.Footnote 49 This accords with what Serge-Thomas Bonino has described as St Thomas’s approach. Just as the human knower must continually return to phantasms (conversio ad phantasmata), so must the theologian continually have recourse to Sacred Scripture (conversio ad Scripturas) as its permanent foundation.Footnote 50
To spell out how the principle of the causality of the maximum applies in this particular case, we might say that it accounts for the headship of Christ primarily with respect to humanity (and secondarily with respect to angels), and only within the narrower scope of the fall. The rigor of the principle only holds true within this narrower sphere and is applied ‘universally’ only within the given economy of human redemption. It does not apply to the angelic drama that took place at the beginning of the world, neither does it apply to the state of humanity prior to the Fall (i.e., Christ’s humanity is not the source of the grace enjoyed by the first parent in the state of integrity).Footnote 51 While this reading of Saint Thomas certainly diminishes the universality of Christ’s causal power (i.e., with respect to all those who are members of the Church), it nevertheless also highlights Saint Thomas’s focus on the revealed economy rather than a purely hypothetical situation that has not in fact obtained. Here, as elsewhere, philosophy ever remains the handmaid of theology. But that this is so should not be surprising given Thomas’s own account of the subordination of all the sciences, including philosophy, to what is divinely revealed.Footnote 52 In this regard, we see just how seriously Thomas, who is first and foremost a theologian, approaches the theological task of fides quarens intellectum.