The doctrine of inseparable operations affirms that the divine persons share one power and efficient causality by which they always act together in producing the outward works of God. Whenever one person acts, all three are acting. Thus, each person's operation cannot be separated from that of the other two persons – hence the phrase ‘inseparable operations’. That language appears in Augustine's De trinitate, for instance, where he emphasises that ‘the Father and the Son and the Spirit, of one substance, God the Creator, omnipotent Trinity, operate inseparably’ or by an ‘inseparable operation’ even when they are manifested distinctly at Christ's baptism in the Father's voice, the Son's flesh and the Spirit's dove.Footnote 1
This doctrine has undergone a recovery of late.Footnote 2 And oftentimes in the shift from the disuse to the recovery of a doctrine, there are clarifications that need to be made about what the doctrine does and does not require from its adherents now that it is back. In the case of inseparable operations in particular, it is important to clarify that it is not so austere as to flatten out all trinitarian distinctions that can be observed in the economy of salvation. For example, each of the divine persons still has his own unique mode of acting in God himself and in the economy: the Father through the Son and the Spirit; the Son from the Father and through the Spirit; the Spirit from the Father and the Son. Furthermore, while there is one efficient causality by which the persons accomplish the works of God, one of God's effects can have a certain relation to just one divine person. At Christ's baptism, the sound of the paternal speech is produced by all three persons, but this effect comes to rest upon the Father or manifest the Father alone. Likewise, the flesh of Christ is produced by all three persons, but this effect comes to rest upon the Son and even subsist in the Son alone. And the dove is produced by all three persons, but this effect comes to rest upon or manifest the Spirit alone.Footnote 3
Within the context of exploring what the doctrine of inseparable operations does and does not require, I would like to focus here on a question that concerns the incarnation, namely, whether the common operation of the divine persons problematises the notion that the human operation of Christ belongs to the Son alone. At first it might seem as if this question could be answered rather quickly by appealing to the distinction between the divine and human operations of Christ, the former belonging to all three divine persons and the latter belonging to the Son alone. However, some of the material in Adonis Vidu's recent book on inseparable operations draws attention to certain lingering issues that warrant a closer look.
Vidu puts the question this way: ‘Who is the subject of Christ's human activity? Are the human actions of Jesus to be attributed to the Son exclusively, or to the whole Trinity?’ Or, ‘Is there an exclusive causality exercised by the eternal Son, by one of the Trinity, proceeding through his human nature towards his human works, a causality in which the other divine persons do not have a share?’Footnote 4 Vidu asserts, ‘There is universal consensus that the human activity of Christ is to be ascribed to the Logos’. ‘However’, he continues, ‘it remains something of an open question whether this attribution is proper or appropriated’.Footnote 5
In seeking to uphold the one causality and operation of the divine persons, Vidu concludes that the human operation or actus secundus of Christ is only appropriated to the Son. For Vidu, the human nature and its ‘germinal energy’ or actus primus are proper to the Son (who alone is incarnate). For that reason, the human operation can still be located in the Son and have a distinctly filial mode. At the same time, in Vidu's account, the human operation or actus secundus, by which the natural or ‘germinal’ energy of Christ's humanity is directed toward a given work, is something moved and actuated by all three divine persons and thus only appropriated to the Son. In this respect, Vidu suggests that all three divine persons may be considered the subjects of Christ's human action.Footnote 6
In my judgement, there is a need to pause here and consider further whether the common operation of the divine persons requires the idea that the human operation or actus secundus of Christ is not proper but only appropriated to the Son. While it is certainly important to uphold the common essence, power, and operation of the divine persons, a misstep here risks undermining the integrity of Christ's human agency, by which he represents us human beings and fulfils his mediatorial office. I will argue that the common operation of the divine persons does not require the idea that Christ's human operation or actus secundus belongs to all three divine persons. Positively, affirming that Christ's human operation or actus secundus is proper (not merely appropriated) to the Son is vital to understanding the integrity, personalisation and filial character of Christ's human action. In other words, affirming the human operation of the Son alone is foundational to being able to say that there is someone, a new Adam and elder brother, who acts on our behalf.
I take it that Professor Vidu and I are traveling in the same general direction in trinitarian theology, so, if there is an implicit critique in what follows, it is a specific and friendly one. In any event, I will concentrate on offering a positive description of the coherence of the common operation of the Trinity and the human operation of the Son alone. My thesis is that all three divine persons move and support the Son's human operation while the Son alone is the proper subject of his human operation. In order to substantiate this thesis, I will consider two main issues in the subsequent sections: (1) the relationship between divine movement and human energy and (2) the relationship between nature and person in Christ's human action.
Divine movement and human energy
As Creator and first mover, God initiates any movement and action that takes place in the life of his creatures. As Paul puts it in Acts, ‘in him we live and move [κινούμɛθα] and exist’ (17:28).Footnote 7 In other words, it is only by God's sustaining power and prompting that we undertake our various forms of action.Footnote 8 Paul sees this realised in a special way in his own apostolic ministry. After calling himself the least of the apostles in 1 Corinthians 15, he goes on to say, ‘But by the grace of God I am what I am, and his grace to me came not in vain, but I laboured even more than all of them [the other apostles], but not I, but the grace of God with me’ (15:10). Similarly, in Colossians 1, Paul says that when he teaches others he labours ‘agonising according to [Christ's] energy which energises in me in power’ (vv. 28–29). Moreover, Paul anticipates and discerns the inward movement of God in those to whom he ministers. There are differences of spiritual gifts or works (ἐνɛργημάτων) but ‘the same God who works [or “energises”, ἐνɛργῶν] all things in all’ (1 Cor. 12:6). One and the same Spirit ‘works’ or ‘energizes’ all these things, distributing to each believer just as he wills (12.11). Moreover, the inward movement or energizing of God is the reason that believers actually work out their salvation, for God is the one ‘working’ or ‘energizing’ (ὁ ἐνɛργῶν) in believers so that believers themselves go on ‘to will and to energize [ἐνɛργɛῖν]’ (Phil. 2:12–13).
This biblical material presses us to reflect a little more on what it means that God moves or energises within human beings, who then have energies of their own. Movement is something that can be described from the side of the one moving or from the side of the one being moved. Movement on the part of the mover is an action whereby one somehow affects another; movement on the part of the one moved is a passion or a being-affected so that one goes from a state of passivity or incompleteness towards a state of actualisation or activity.Footnote 9 The nature of movement indicates that the one moved is moved by another. That is, what is moved, which is initially passive and as such produces no action or change, has to be moved by someone else, or at least by another part of itself that is already active (which part, if it too was once passive, must then have been moved or activated by yet another). This is why creatures, who are subject to passivity and are not a se, ultimately depend upon the active movement of the eternal God who creates them and moves them to act.Footnote 10
Of course, the scriptural material just mentioned reminds us that the eternal God who created us continues to move us. He does not merely move a first creature and then leave that creature alone to prompt subsequent movements and changes in the world. Indeed, God himself sustains all his creatures, who, without God sustaining and moving, would not endure, operate or move others. Thus, whether by himself or by secondary causes, God still moves human beings to act. This is why Paul speaks of God even now ‘energising’ believers.
Movement on the part of the mover, then, is an energy or action, an application or use of the agent's power to the production of a certain effect.Footnote 11 But it is not to be overlooked that the God who energises within human beings – in the sense of acting to prod them from passivity to activity – in so doing produces a resultant energy or activity, an actus secundus, that is proper to a human subject. By God's creative action, there is a created nature's act of being, which, historically, is called esse or actus primus (existence). And, by God's moving action, there is within a created nature (and then issuing from it) the creature's application of its powers to the production of certain effects, which, historically, is called energy, action, or actus secundus.Footnote 12 Following on the prevenient movement of God, this action or actus secundus is facilitated and shaped by the creature's nature and by any subsequent qualities the creature may have acquired. In this respect, while God does act to prompt the action or actus secundus of a human being, that person's human nature is the formal cause of the actus secundus and thus that person himself or herself, operating according to the person's own counsel, is the subject of the actus secundus (i.e. the one who thinks, wills, eats, drinks, obeys and is responsible for doing so).Footnote 13
There are of course places in Scripture where God is said to do something that a creature does (e.g. 2 Sam. 24:1; 1 Chron. 21:1; Isa. 53:10; Acts 2:23; 4:27–28). Those places attest that God enables and moves creatures to act and directs their actions towards the accomplishment of his purposes. But that is still different from God being the proper or immediate subject of human actions. While the word ‘subject’ can have various significations, in this case it denotes an individual substance that subsists by itself, terminates its nature and is constituted within a certain kind by its nature.Footnote 14 Though God can be said broadly to support and sustain created natures (so Acts 17:18; Col. 1:17), the proper subject of a human nature and consequent human actions is a subject who terminates and is actually constituted a human being by the human nature.Footnote 15
This line of thought is maintained in early Reformed accounts of divine providence that make use of concepts like ‘physical premotion’, ‘precursus’ and ‘concursus’.Footnote 16 All three of those terms convey something about God moving creatures to act. Praemotio physica signifies God exciting a creature to action or actus secundus. The same act of God exciting is also sometimes called praecursus, for it is a matter of God ‘running before’ the creature to lead the creature into action. And the same act of God (or a closely related act of God) is also called concursus, for it is a matter of God sustaining the creature's activity through to the point of producing an effect.Footnote 17 Though such descriptions of divine providence acknowledge that God's action and the human person's action are finally unified with respect to their terminus (one and the same effect), it remains that only the human person is the proper subject of the human action.Footnote 18 In this regard,
God cannot be said to produce the actions of secondary causes, for example, to heat or to walk. Because those actions belong to God only efficiently, but [they belong] to creatures not only efficiently but also formally and subjectively, in which manner creatures are better denominated by [those actions] than God himself.Footnote 19
For the purposes of this essay, the point is that God's moving action and the creature's subsequent action or actus secundus remain distinct. The creature alone is the formal cause and proper subject of his or her actus secundus. Accordingly, since each divine operation, including God's movement of creatures, is shared by all three divine persons, all three divine persons move, support and accomplish things through Christ's human operation, but only the person who subsists in the flesh and is constituted a man (the Son) can be the proper subject of that operation. Though the person of the Son is an antecedent person – a complete person before the incarnation – he is nevertheless constituted a man by the assumption of his human nature.Footnote 20 Indeed, he alone of the divine persons is constituted a man. Therefore, he alone can be the proper subject of his human actions. This claim can be filled out more by considering the relationship between nature and person in Christ's human action.
Nature and person in Christ's human action
In order to confirm that the Son alone is the subject of Christ's human action, it will be useful to elaborate on the relationship between the human nature and the person of the Son. First I will try to clarify what the term ‘nature’ means, and then I will try to connect this explanation to Christ's human operation.
The word ‘nature’ (φύσις) as it appears in both biblical and philosophical literature is multi-faceted.Footnote 21 ‘Nature’ can signify ‘birth’ or the endowments and conditions that follow from birth (see Rom. 2:14, 27; 11:21, 24; Gal. 2:15; Eph. 2:3; cf. 2 Pet. 2:12; Jude 10).Footnote 22 Relatedly, ‘nature’ can also signify the essential constitution of something, or what something is (cf. Gal. 4:8; Jas. 3:7; 2 Pet. 1:4), treated especially as a principle of motion, operation and orientation towards an end.Footnote 23 The term ‘nature’ can also signify more broadly the divinely appointed order of things (see Rom. 1:26; 1 Cor. 11:14).
Nature as essence or quiddity – ‘what-ness’ with a view to action – is the most relevant usage for the present line of thought. It can be treated in at least three ways. First, nature as essence or quiddity can be treated as an abstract universal, an idea in the divine intellect or a concept in the human intellect. Second, nature as essence or quiddity can be treated as something present in individuals of the same kind but understood as common to all of them. Third, nature can be treated as essence or quiddity just in a particular individual.Footnote 24
Nature or essence treated in the first way, as an abstract universal, does not exist in its own right, so of course it does not perform actions. For example, humanity as a universal separate from individual human beings does not exist or perform actions. Nature or essence treated in the second and third ways is really the same, the only distinction being that in the second way the intellect conceives the nature's commonality across multiple individuals. And even in the case of nature as it is present in an individual, nature per se does not perform actions. Strictly speaking, we do not say, for example, that Peter's humanity denied Jesus while Jesus’ humanity obeyed the Father. Instead, we say that Peter denied Jesus while Jesus obeyed the Father. That notion is captured in the axiom actus sunt suppositorum (actions belong to individual substances or ‘supposits’).Footnote 25
On the one hand, human nature itself supplies a human being's rational intellect, will and various other powers common to humankind. Human nature itself establishes a human being's telos, limitations and initial aptitudes. On the other hand, it is the person constituted a human being by the human nature who exercises the faculties and powers of the nature. That is, someone of a human nature determined in a unique mode of being (with a unique portion of matter, unique act of existing, unique accidents and disposition) is the one exercising the faculties and powers.Footnote 26 This arguably applies even at the level of basic, subconscious acts such as breathing and digesting. It applies all the more with respect to a human being's exercise of free choice, not least when one human being, the man Christ Jesus, is exercising free choice virtuously and meritoriously for the benefit of others.Footnote 27
The preceding section about divine movement and human energy emphasised that one must in fact be human in order to be the proper subject of human actions or actus secundi. To complement that point, this present section is emphasising that it is not a human nature per se but rather an individual person (i.e. a human nature determined in a certain mode of being) that will be such a subject performing human actions. How does all of this connect to Christology and the question of the human operation of the Son? I think at least two important points follow.
First, this line of thought entails that in the incarnation it is not the human nature per se that performs human actions. Nor is it the case that all three divine persons wield a bare human nature through which human effects might come into being. Rather the person of the Son, and the Son alone, exercises the capacities of his human nature and performs human actions. This is attested in the Christology of John of Damascus, for example. On the one hand, when John speaks about Christ's two wills and theandric energy, he is careful to specify that will and energy themselves pertain to natures, so Christ has two natural wills and two natural energies.Footnote 28 In order to distinguish the two natural energies, there are even points at which John might give the impression that Christ's two natures per se perform actions.Footnote 29 On the other hand, however, John is equally careful to state that, since there is the one ὑπόστασις of Christ, it is ‘one and the same willing and energising naturally’.Footnote 30 The will and energy per se do not will and energise, but each of these is a power ‘according to which’ (καθ’ ἣν) Christ wills or energises.Footnote 31 Thus, John points out that there is a distinction to be drawn between ‘energy’ and ‘the one energising’ (ἐνɛργῶν). While energy goes forth from the ‘energetic’ nature, the ὑπόστασις is nevertheless the ‘the one energising’ and ‘the one using’ (ὁ κɛχρημένος) the energy.Footnote 32 This sort of distinction between the power or energy that accompanies nature and the one who exercises or uses such power and energy is expressed later by the distinction between a principium quo and principium quod – a principle ‘by which’ one acts and a principle or agent ‘which’ does the acting.Footnote 33
Second, nature by itself does not contain a proper mode of being or acting. The proper mode of being and thus the proper mode of acting is supplied by a person or that which individuates a person. As John of Damascus puts it,
to will and to will in a certain manner [θέλɛιν καὶ πῶς θέλɛιν] are not the same thing. For, on the one hand, to will belongs to nature just as also to see (for it is present in all men), but, on the other hand, to will in a certain manner does not belong to nature but to our judgment [γνώμη], and to see in a certain manner, well or badly (for not all men will likewise or see likewise). This we will grant also about energies. For to will in a certain manner, to see in a certain manner, to energise in a certain manner belongs to the use of the willing and the seeing and the energising, which is present in only the one using [them].Footnote 34
Accordingly, if per impossibile a bare human nature were the subject of the human action in the incarnation, there would be no filial mode of the human action. Moreover, if, hypothetically, all three divine persons had taken on flesh and were the subjects of the human action in the incarnation, there would be no distinctly or exclusively filial mode of the human action. It must be that the Son himself, ever existing and acting within his relation to the Father, is the subject of Christ's human action in order for there to be a distinctly filial mode of acting in the incarnation.
This commitment to the human operation of the Son alone is upheld in accounts of the Son's humanity as an instrument of deity.Footnote 35 In Aquinas’ explanation of the instrumentality of the Son's humanity, he observes a distinction between an ‘external’ and ‘common’ instrument like an axe and a ‘conjoined’ and ‘proper’ instrument like a human hand is to a human soul. The former can be used by many, but the latter belongs properly to the one whose hand it is. This latter illustration is the one that applies to Christ's humanity.Footnote 36 To be sure, identifying Christ's humanity as an instrument of deity emphasises that the humanity is ‘moved and ruled by the divine’. But even in the ‘use’ of the human operation by the whole Trinity, there is still a ‘double action’ to be noted: one action of the humanity according to its proper form and virtue and another according to the fact that the humanity is moved by another.Footnote 37 Who, then, is the subject of the distinctly human operation that is utilised and ruled by the whole Trinity? Aquinas is abundantly clear about this when he commends the teaching of Dionysius in the work De divinis nominibus:
in these things, which pertain to [Christ's] human operation, ‘the Father and Holy Spirit share in no way unless someone will have said “according to the most kind and merciful will”’, namely, inasmuch as the Father and Holy Spirit from their own mercy have willed Christ to do and to suffer human things….So it can be seen, therefore, that his human operation is one thing, in which the Father and Holy Spirit do not share except according to the agreement of their own mercy. And his divine operation, insofar as he is the Word of God, is another thing, in which the Father and Holy Spirit share.Footnote 38
Not sharing in the human operation of the Logos except in divine agreement and sharing fully in the divine operation of the Logos – that is the right description of the involvement of the Father and the Spirit, and it is good news for us who need a mediator who is man and authentically acts as man on our behalf.
Conclusion
In this attempt to bring together the teaching of inseparable operations and the human operation of the Son alone, I have sought to clarify the coherence of these two elements of Christian doctrine by examining the relationship between divine movement and human energy and the relationship between the human nature of the Son and the person of the Son in Christ's human action. While all three divine persons always move and work together in the case of creaturely operation, this movement produces a resultant energy and energising within the creature. The formal cause of that resultant energy and energising is the created nature, which entails that only the one constituted by that nature is the proper subject of the operation. Thus, while all three divine persons move and work in and through creaturely operation, only the Son, who is not a creature but is constituted a man by his human nature, is the subject of his human operation. In addition, while the human nature of Christ is the locus of Christ's human powers of acting, it is the person of the Son, and the Son alone, who exercises these powers and does the acting. A subject who is himself human is the one who exercises these powers, which secures the integrity of Christ's human action and thus the integrity of his mediatorial work. And that acting subject is God the Son in particular, which secures the filial mode of the human action, a filial mode by virtue of which Christ discloses the Father to us and, in uniting us to himself, conforms us to himself as the exemplar of our sonship (see e.g. John 8:28; 17:26; Rom. 8:29; Gal. 3:26–27).Footnote 39
It seems to me that this examination of how to utilise the doctrine of inseparable operations may contain some broader implications for theological study. In our day, retrieval of earlier accounts of Christian doctrine is widespread, which is, in my view, a salutary development. For a case can be made that theologians of earlier centuries were very often wiser and more biblical than we are. However, in order to listen well to earlier accounts of Christian doctrine, it is necessary to distinguish between what was taught in the past and what might seem most forcefully opposed to contemporary trends that one wishes to combat. With that distinction in place, it may be that our recoveries of historic doctrines will be more biblical, more capacious and more calibrated to address the theological and spiritual needs of the people of God today.
