Trinitarian theology is looking for an analogy which gives due respect to its subject, and which enables it to bring an authentic procession within God to light. Refining on what the analogy must do, St Thomas adds that it must enable one to grasp an 'immanent procession'. The starting-point of the Trinitarian treatise is the idea of 'immanent procession'. Thomas' reflection is based on an interpretation of the problems of Arianism and Sabellianism: because they conceive procession like a transitive action, these heterodox theories cannot work out how a Son could genuinely exist within God. As we mentioned in relation to the structure of the treatise,21 Thomas appropriated Aristotle's distinction between two kinds of actions: 'immanent' action, which remains within the acting subject (such as knowing, willing, and feeling), and 'transitive' action which passes over (transit) to a reality external to itself (such as heating, constructing, and making).22 In both cases, the action gives rise to a procession:
21 See above, in Chapter 3, 'Immanent and Economic Trinity'.
22 See especially ST I, q. 27, a. 1; SCG II, ch. 1; De potentia, q. 9, a. 9; q. 10, a. 1.
procession of an interior reality, for the immanent action, and procession of an external reality, for the transitive action. One must recognize two analogous kinds of actions in God: the Trinitarian processions, in the one case, and the actions of creation and government in the other.23
The example constantly used by St Thomas is that of the architect: the immanent action takes place when the architect mentally conceives the plan of the building which he is going to construct, and he wills its construction; then, in the transitive action, the architect concretely realizes his plan by getting the building constructed. The next step is that the transitive action, or 'procession ad extra, implies a difference between the agent and the reality which proceeds from his action.24 If one applies this to the processions of the divine persons, then 'the persons who proceed from it will be external to the divine nature', just as the house is of a different nature from the mind of the architect who conceives and wills it.25 For Thomas, this is the trap into which both Arianism and Sabellianism fall, in their own different ways:
Some have understood this procession in the sense of an eVect proceeding from its cause; so Arius took it, saying that the Son proceeds from the Father as the Wrst amongst his creatures, and that the Holy Spirit proceeds from the Father and the Son as the creature of both. But then, neither the Son nor the Holy Spirit would be true God . . . Others take the procession to mean the cause proceeding to the eVect, as moving it, or impressing its own likeness on it; in which sense it was understood by Sabellius, who said that God the Father is called Son in assuming flesh from the Virgin Mary, and that the Father also is called Holy Spirit in sanctifying the rational creature and moving it to life.26
By conceiving the generation of the Son as if it were a transitive action, Arianism sets up an a priori interdiction against understanding the authentic divinity of the Son and the Holy Spirit. Sabellianism does something analogous from the opposite end of the spectrum: it allows one to maintain the divinity of the Son and Holy Spirit but only by conXating them with the Father, treating them as the modes through which the Father acts in the world. It is no surprise that Arianism and Sabellianism both make the same misjudgement. It is true that, in trying to avoid Sabellianism, Arius went for the opposite mistake,27 but nevertheless the contraries meet on one point: both connect the generation of the Son to an 'external nature',28 Arius relating it to the production of a creature, and Sabellius to incarnation. Thus: 'Careful
23 Depotentia, q. 10, a. 1; SCG II, ch. 1 (no. 854).
24 ST I, q. 27, a. 1, ad 2. 25 Depotentia, q. 9, a. 9. 26 ST I, q. 27, a. 1.
27 SCG IV, ch. 6 (no. 3387); De rationibus fidei, ch. 9: 'Arius, trying to avoid Sabellius' error, which conflated the persons of the holy Trinity, fell into the opposite error, dividing the essence of the deity.'
examination shows that Arius and Sabellius understood the procession as something brought about within an external reality.'^
These thoughts are very useful for understanding what Thomas is aiming at here. His consideration of the processions is undergirded by the necessity of creating an alternative to the two outstanding Trinitarian heresies. As he explains in the De potentia:
The ancient doctors of the faith were compelled to discuss matters of faith because the heretics drove them to it. Thus Arius thought 'holding one's existence from another' is incompatible with the divine nature. Since Scripture teaches that the Son and the Holy Spirit hold their existence from another, Arius maintained that the Son and the Holy Spirit are creatures. In order to refute this error the holy Fathers had to show that it is not impossible for someone to proceed from God the Father and yet be consubstantial with him, inasmuch as he receives from him the same nature as the Father has himself.3o
The exigence of defending the faith supplies the opportunity to unfold a Catholic doctrine of the Trinitarian processions. As we saw above, Thomas had already formulated the same intention regarding the plurality of the divine 'persons'. He conceived his own meditation as an extension of the Fathers', both manifesting the true faith as against the mire of heresy. The heresies are linked to a philosophical misjudgement: St Thomas explains elsewhere that the Arians did not want to believe in the divinity of the Son and that they could not understand it: so their position was motivated by deliberate rejection, but also by an intellectual difficulty.3! He does not present the diverse aspects of Arianism and Sabellianism in detail in q. 27 of the Summa3 but he does propose a doctrinal interpretation of their common error, with the aim of finding a speculative route which, by enabling us to avoid their dead-end, permits us to contemplate the truth. This is why Thomas chose to build his Trinitarian treatise on the immanent processions of the word and of love.
Was this article helpful?