Wednesday, 17 November 2010

Question 31 - Terms Referring to Unity and Plurality in God

Why this Question Matters.

Aquinas has established that the persons of the Trinity are subsisting relations, the relations being derived from the scriptural data concerning processions. He now moves on to discuss what we can say about various aspects of the Trinity. The character and focus of this question may, at first reading, appear to be slightly odd. However, it reflects the keen interest that medieval philosophy took in the functioning of language and in the relationship between language and the traditional areas of philosophy. (In these concerns, medieval philosophy shows a fascinating similarity to many aspects of the linguistic philosophy of the twentieth century). The choice of subjects for the articles of this question reflects some of the most important and lasting controversies in the Middle Ages about the use of language when applied to God. Aquinas’s immediate concern in this question is revealed in the body of the second article: “heresy arises from words that are used incorrectly” (quoting St. Jerome) and “There is no other place where error is more dangerous, where questions are asked more rigorously, or where anything more fruitful is found” (quoting St. Augustine). So then, what can we say about God as Trinity and what must we avoid saying?

The Thread of the Argument

A1: Aquinas has shown that we can attribute a plurality of persons to God; in this article he demonstrates that we can be more specific and attribute the name “Trinity” to this plurality of persons. The argument is very straightforward: the name “Trinity” simply signifies determinately what the word “plurality” signifies indeterminately. The bulk of the article is devoted to answering a number of linguistic objections to this attribution.

As an example, the first objection suggests that names must either signify the substance of God or a relation within God. The word “Trinity”, taken as a name, can’t signify the substance because this would attribute the substance of God individually to each person (leading to tri-theism). However it can’t signify a particular one of the relations because it clearly is not a referential word. Although Aquinas admits that etymologically the word “Trinity” would appear to refer to the single essence of the three persons, as it is used in the context of God it refers to the number of persons in the single essence. The objection has set up a false dichotomy.

A2: The question of whether we may say that the “Son is other than the Father” had a lengthy pedigree in medieval times; it almost became a standard scholastic exercise. The fundamental dichotomy is that we want to be able to say it in order to distinguish between these two persons of the Trinity, but we must beware of the possibility of it expressing the idea that the Father and the Son are different in the sense of being substantially different. Aquinas uses this background to chart a terminological course between the Arian error of dividing the substance of God and the Sabellian error of conflating the persons. In thinking about Arianism, Aquinas teaches that we must avoid words like “diverse”, “different”, “separate”, “divided”, “disparate”, “alien” or “discrepant” because all of these are too suggestive of various erroneous positions. However, we can use the word “distinct” especially if we note that it is referring to the relations. He comes up with a similar list when considering Sabellianism. Essentially, Aquinas is attempting to build a list of allowable words and their definitions in order to avoid the sort of misunderstandings that arose frequently in the past.

In addition Aquinas applies the principle of expositio reverentialis by saying that when we come across an orthodox authority who uses language imprecisely we must recognize that we have to understand that language in an informal sense, substituting correct formal terminology as we read.

Having considered such terminology, Aquinas concludes that it is reasonable to say that the Son is other than (alius) the Father because the word implies only a distinction of supposita rather than of substance. It’s worth noting that in the reply to the fourth objection Aquinas is so precise as to say that alius (i.e. the masculine grammatical gender) refers to the supposita and therefore acceptable whereas aliud (i.e. the neuter grammatical gender) refers to the common essence and therefore cannot be used.

A3: The next article tackles the linguistic question of how the word “alone” can be used when talking about God’s essence. In order to address this question Aquinas introduces the grammatical ideas of categorematic and syncategorematic terms: a term is categorematic if it can stand as the subject or predicate of a proposition. So in the phrase “a white elephant” the term “white” (acting as a predicate) signifies something absolutely with respect to the subject “elephant”. On the other hand, a syncategorematic term is one that is not categorematic. Words like “of” and “and”, “all” or “none” are usually (always?) syncategorematic. A word like “alone” can act in both ways: compare “Socrates is alone” with “Socrates alone is writing”: in the first proposition “alone” is functioning as a predicate describing the fact that Socrates is on his own. In the second proposition Socrates need not be alone; we simply learn that Socrates is the only one writing.

Aquinas observes that we can use “alone” syncategorematically when speaking of God’s essence (“God alone is eternal”, for example) but not categorematically (“God is alone” for example). To do the latter would contradict the conclusion reached in the previous article.

A4: Having dealt with the question of how the word “alone” may be used in propositions about the divine substance, Aquinas now asks the same question of propositions about the divine persons. If we take the proposition “The Father alone is God” then we can immediately see that a syncategorematic reading does not work as it attributes solitariness to the Father (against the teaching of Article 2). Even when we read it syncategorematically, we have to be aware of different possible meanings. The correct meaning is equivalent to “He, being the only one who is Father, is God”. Aquinas points out that this is such a subtle use of grammar that it is dangerous and that such phrases should not be left to stand on their own but should have explanations attached. Aquinas provides precisely such explanations for a number of common examples in the replies to the objections.

Handy Concepts

  • Aquinas is guided again in this question by the need to sail between the twin Trinitarian errors of Arianism and Sabellianism.
  • Aquinas practises and preaches the doctrine of “expositio reverentialis”: we must read orthodox authorities with sympathy and reverence, realizing that although the terminology may be misleading, or the ideas insufficiently developed, the kernel of the ideas presented is correct and what the authority writes should be built upon rather than demolished.
  • A term is categorematic if it can stand as the subject or predicate of a proposition. Otherwise it is syncategorematic. Words such as “alone” can only be used syncategorematically of the substance and persons of God and even then should be used with care and glossed precisely.


  • Why does Aquinas not refer to the idea of transcendental multiplicity in the first article?
  • This question may appear to be reserved only to grammar nerds, but the underlying principle that sloppy use of language can make a complete hash of theology is a vitally important one.

Monday, 15 November 2010

Question 30 - The Plurality of Divine Persons

Why this Question Matters.

God is one and yet God is three. In this simple statement of Trinitarian faith lays one of the greatest mysteries of Christianity. That it is true is a matter of faith and, Aquinas believes, it cannot be demonstrated on purely metaphysical grounds. Still, we can ask whether it can be considered coherent. Aquinas has identified that scripture reveals to us that there are real subsisting relations within the Godhead and that we can identify these with the “persons” identified in the creedal statements of the Church. Aquinas now focuses on the question of plurality in the Godhead with respect to the persons: is there plurality? How many persons are there in the Godhead? In what sense can we even think about using number when it comes to the persons of the Godhead?

The Thread of the Argument

A1: In the light of the Christian teaching on the unity and simplicity of God, the first question to ask is whether it makes sense to talk about a plurality of persons in God. Of course the Christian Tradition, here illustrated by the Athanasian Creed, insists upon such a plurality and Aquinas aligns his teaching with this. As the notion of “person” corresponds to a relation subsisting as a reality in the Godhead and as there are a plurality of such relations, then it makes sense to talk of a plurality of persons in God.

The reply to the first objection sees Aquinas continuing his explanation of the possibilities for confusion in the Greek and Latin terminology. The second objection asks why, when the absolute properties of God (such as goodness and wisdom) do not lead to differentiation, relations do lead to such distinctions. Aquinas recalls the fundamental difference between absolute and relative properties: the very being of relations is founded in their pointing to something else; they exist in opposition. It is this that creates the multiplicity from relations. Continuing this theme, for the third objection Aquinas points out that a plurality of absolute things (such as goodness, wisdom) does not create plurality in God because of His simplicity. But relations, because of their pointing-to-the-other, do not create the type of composition of thing-and-property that would contradict simplicity. Finally number, by its very definition, would seem to create parts-within-a-whole. Aquinas replies that, at the very least, we can attribute number as an intellectual construct to God because such a construct exists in the intellect rather than in the thing itself. He postpones until Question 42 Article 4 a discussion of why number existing in things (as when we count parts of a whole) does not pose a challenge when we apply it to the Trinity.

A2: Having accepted that we can reasonably talk about persons in the Godhead, we must continue the enquiry of Question 27 Article 5 and Question 28 Article 4 and check that Aquinas’s Trinitarian theory gives us the “right” number of persons. Aquinas argues that the real distinctions among the persons arise from their being in relational opposition to one another; therefore all he has to do is to count the genuine relation oppositions. The technical difficulty arises from the doctrine that the Holy Spirit proceeds from the Father and the Son (the famous filioque clause of the creed). Unless care is taken over the relational opposites associated with the Holy Spirit, there will be some double counting.

The relations to sort out are the spiration and the procession (the latter in the sense specialized to the Holy Spirit). First Aquinas points out that procession cannot be associated with the Father and/or the Son, since if this were so the relations of paternity and sonship (based on intellectual procession) would be founded on the procession of the will. Therefore procession is associated with the Holy Spirit and spiration is associated with both the Father and the Son. In the reply to the first objection, Aquinas goes a little bit further and explains that whilst paternity, filiation and procession are personal properties (i.e. they constitute the persons), spiration is not as it neither belongs to a single person nor constitutes a single person.

A3: When we talk about plurality or number in the Godhead we are faced with one of the central mysteries of the Trinity: how can there be just one God (who is absolutely simple) and yet there be these three “persons” in the Godhead. So far, we may have been unconsciously assuming that we apply the concept of number univocally to God and to creatures; but is this valid? What does it mean to apply number to God? Do numerical terms imply some reality in God?

Aquinas observes that the notion of plurality arises in two ways. On the one hand, material things can be divided into subsets and from this we associate number with quantity. On the other hand there is a transcendental notion of plurality that arises from dividing being into the one and the many. This latter is the only sort of plurality that makes sense for immaterial things. Aquinas claims that previous authors have become muddled on this issue by attempting to apply the first notion of number to God. Aquinas rejects this line of thinking, suggesting that if it is followed one can only make sense of numerical claims about God in terms of metaphor.

Aquinas therefore considers number as applied to the Godhead in terms of the transcendental notions of unity and multiplicity. Aquinas has already applied the transcendental notion of unity (convertible with being) to God’s essence in Question 11 Article 1: When we say that God is one, we are positively affirming that His being is an undivided reality. Here Aquinas applies transcendental multiplicity to the Godhead: what this affirms is that each person is undivided and that each person is not some other person. Put in this way, Aquinas claims that we can then affirm number to the Godhead as a reality and not just as a metaphor or simply as an intellectual construct. Moreover, as Aquinas lays out in his reply to the third objection, unity does not exclude multiplicity but rather excludes division. Similarly, multiplicity does not exclude unity but rather division between the realities out of which the multiplicity is formed.

A4: The final article in this question is a somewhat technical exploration of how the notion of “person” can be considered common to the three persons. That there might be a problem is explored in the objections: for example, only essence is common to the three persons, therefore personhood cannot be common to them. Similarly, if “person” is common to the three then it is either a real or conceptual commonality. If it is only a conceptual commonality then there is really only one person; if it is a real commonality then this would seem to set up “person” as being a universal with God possessing particularity, or genus and species, with respect to this universal (see Question 3 Article 5).

Aquinas points out that when we talk about creatures such as men, the name “person” is common to them, but it is a different sort of commonality than that implied by saying that they share the same essence. It is not a real commonality, but the type of commonality that it is has been something over which various authors have disagreed. Aquinas argues that this commonality is a commonality of concept, pointing towards the notion of an indeterminate individual (such as we refer to when we say “a man” without any particular man in mind). Even with this vagueness, in the example of “a man”, we point towards a common nature, together with a particular mode of existing as a per se individual. Now when we use the term “person” (as opposed to “a man”) things are slightly different: we are pointing towards a reality that subsists in a particular nature. This is what is conceptually common to all of the divine persons.

In answer to the objection against conceptual commonality, Aquinas points out that even when we consider creatures, commonality of personhood does not set up commonality of genus or species, so the objection fails. Moreover, things are simply different when we consider the divine: the persons share a common being whereas creatures particularizing a universal have different beings.

Handy Concepts

  • “Persons” in the Godhead correspond to subsisting relations and therefore we can talk about a plurality of such persons.
  • Spiration is a real relation in the Godhead but does not belong to or constitute a person; therefore the four real relations in the Godhead correspond to three persons.
  • In considering number and plurality to arise out of the division of being into the one and the many, Aquinas is following Aristotle’s Metaphysics.
  • The discussion of number as applied to the Godhead had rumbled on for many years during the middle ages. A good discussion of the background to Aquinas’s treatment can be found in Chapter 7 of Emery’s “The Trinitarian Theology of St. Thomas Aquinas”.


  • In the sed contra of Article 2, Aquinas quotes the famous Johannine Comma as an authority in favour of the tri-personality of God. Although the canonicity of this writing is disputed, it can still be considered at the very least as an ancient authority.
  • Aquinas’s reduction of the four real relations in the Godhead to the three persons may seem a bit of an ad-hoc sleight of hand to accommodate the filioque. However, one might note that the problem doesn’t simply go away if one insists that the Holy Spirit proceeds only from the Father, and even might be considered worse if this were the case. Having two real relations (paternity and spiration) associated with the Father would seem to associate two persons with the Father!
  • In the de potentia (Q.9 A.5) Aquinas writes that “The plurality of persons in God is an article of faith, and natural human reason is unable to investigate and adequately understand it.” We emphasize again that Aquinas is not trying here to derive this truth of faith from reason but is trying to show that it is at least rationally coherent.
  • The difficult notion of transcendental multiplicity is discussed at more length in Aquinas’s de potentia Q.9 A.7.

Saturday, 13 November 2010

Question 29 - The Divine Persons


Aquinas has now established that there are real relations in God and that, as a consequence of divine simplicity, these relations are substantial. He has also identified the connections between the notions of procession and relations. Having dealt with these highly abstract concepts, Aquinas now devotes Questions 29-38 to an understanding of the idea of “persons” within the Godhead, connecting this notion with those of procession and relation, and providing a detailed discussion of each person. In Questions 39-43 he will then discuss in more detail the relations between the persons of the Godhead.

Why this Question Matters.

Aquinas is now aiming at a metaphysical elucidation of the classical Christian affirmation that God is three persons (Gk. hypostases) in one substance (Gk. ousia). The next step in this process is for him to address the question of what is meant in this context by a “person”. Aquinas has available to him a number of different definitions of personhood current in medieval theology; the one he favours is that of Boethius: “The person is an individual substance of a rational nature”. One of the major strengths of this definition is that it applies not only to human persons but can also be applied, by analogy, to angels and to divine persons; it is an expansive and inclusive definition. However, Aquinas has to explain carefully what the terms of the definition mean as it is easy to misunderstand what it is driving at. Having established a metaphysical definition of “person” he then has to discuss the various Greek and Latin terms used in Trinitarian theology, as to avoid later confusion. Finally, Aquinas delves into how the notion of person applies analogically to God: from this discussion will emerge the critically important idea that the persons within the Godhead are the subsistent relations identified in the previous two questions.

The Thread of the Argument

A1: Aquinas first addresses the suitability of Boethius’ definition of person. He observes that if we consider substances in general (i.e. the genus of substance) then we quickly recognize the fact that we can identify individual substances. Individual substances have the property that they subsist in themselves: they do not require some other substance to specify their being. Contrast an individual substance like a ball with the whiteness of the ball: the ball subsists in itself, but the whiteness (which we are quite entitled to call this whiteness) depends for its being on the ball. Aquinas identifies such substances as primary substances or hypostases. Further, there is a more perfect mode of particularity to be found amongst those substances that are rational; they are in control of their actions. These rational individual substances are what we call persons.

The objections to this article mostly focus on technical issues involved with the definition. For example, if we are taking “substance” in the definition to refer to primary substance, then it would seem redundant to refer to an individual substance. Aquinas replies that the addition of the word “individual” is justified because it adds the property of “not being assumable by another”. Although this may seem odd, Aquinas is thinking of the special case of individuated human nature in Christ: from the definition of Chalcedon we know that Christ is not a human person; His personality is that of the second person of the Trinity. Similarly one might object (on Aristotelian grounds) that the definition should use “essence” instead of “nature”. Aquinas replies that the sense in which “nature” is being used here (slightly different from Aristotle’s use), which is the essence of each particular thing, is better appropriate that the more general term “essence”. The reply to the fifth objection looks forward to Aquinas’ teaching on the soul: a separated substance (such as the soul of a human after death) is an individual with a rational nature but is not a person. Aquinas replies that the soul is a part of a human person and therefore cannot be identified as being a primary substance. It may be an individual, but it is not an individual substance.

A2: Terminology has always provided an obstacle to the understanding of Trinitarian theology. Even when the Doctrine of the Trinity was approaching its definitive conciliar form there was confusion between different theological schools that were using the same words to mean subtly (and sometimes not so subtly!) different things. Therefore, it is always a good idea, before embarking on Trinitarian speculation, to have a session devoted to the defining of terms. In the objections to this article Aquinas gathers together arguments and counter-arguments to suggest that a person, an hypostatis, a subsistent and an essence are really the same things. In a twist of scholastic humour, Aquinas gathers arguments for and against this position from a single author, Boethius, who is also the author from whom he has acquired his definition of person!

In his reply, Aquinas identifies two senses of the word “substance”. In the first sense, the substance of a thing tells us what that thing is: it is a thing’s what-ness or its quiddity. In this sense, substance is the same as the Greek ousia and can be identified with essence. (As an example of this use, in the creed we affirm that the Son is consubstantial with the Father; consubstantial is translating the original Greek term homoousios).

The second sense of the word “substance” is a bit more complicated, but basically refers to an individual thing within the genus of substance. As such, it can be described in a number of different ways. It can be referred to as a suppositum, which is a logical term referring to the thing that underlies some attributes (so, for example, the ball is the suppositum that underlies the property of roundness). Secondly a substance can be called subsistent insofar as it exists as a thing-in-itself and not in another (so the ball subsists but the roundness does not, as it exists in the ball). Thirdly, a substance is a thing-with-a-nature (the ball exhibits the nature of what it is to be a ball). Fourthly, a substance is called a hypostatis or substance in that it underlies its accidents (so the ball underlies the whiteness of the ball).

All that is left to Aquinas now is to specialize these words to the genus of rational substances.

A3: The Athanasian Creed explicitly attributes personhood to the Father, Son and Holy Spirit, but one might ask whether this is a reasonable thing to do. Aquinas replies by saying that subsisting in a rational nature is the most perfect thing in the created world and by the teaching of Question 13 Article 3 it is therefore quite reasonable to attribute personhood to God. We do, of course, have to remember that such an attribution is by way of analogy and that the personhood attributed to God is attributed in a far more excellent way than it is to creatures. Aquinas’s answer to the question set in this article is quite straightforward; the bulk of the interest comes in his replies to the objections.

First of all, one might object that scripture gives us various words and formulations to describe God and that we should not go beyond these. Aquinas admits that “person” is not said of God in scripture but he claims that what personality describes is used many times of God. Moreover, if heretics are to be refuted, then new ways of expressing the ancient faith are quite appropriate. In a similar line, one might object to the very word “person” because its etymological derivation is quite inappropriate to God. But this is to fall into the etymological fallacy; because a word originates in one way this does not imply it necessarily retains such a meaning (especially when it is being used, as here, in a technical sense).

In the reply to the third objection, Aquinas adds an important qualification to what he said about hypostatis in Article 2. In the created world, a substance is called a hypostatis insofar as it underlies its accidents: but in God there are no accidents, so surely we cannot apply the notion of hypostatis to God. Aquinas replies that, when applied to God, we are not thinking of hypostasis in this way but in terms of signifying a subsistent entity. He also relates some history of the terminological arguments in the early Church: as the Greek term “hypostasis” used to be translated as the Latin “substantia” (that is, “substance” or “essence” rather than the later understanding of “subsistence”), confusion arose as the Latins thought the Greeks were attributing three essences to God.

Objection 4 collects together some terminological problems. A rational nature would seem to imply discursive cognition, which is not true of God (Question 14 Article 7); individuation would seem to imply individuation by matter, again not applicable to God; God does not have any accidents, so how can we call Him a substance? Aquinas answers the first and third of these by pointing out that rationality can be thought of in a much wider sense and that substance refers, more fundamentally, to per se existence. In answering the second objection, Aquinas introduces the important idea of individuation as incommunicability. An individual is one for whom it makes no sense to attribute its properties to something else. So, for example, it would make no sense to attribute my thoughts to some other person.

Aquinas’s answers to objections 2-4 emphasize the importance of understanding that in Trinitarian theology terms are borrowed from the metaphysics of created reality and are given subtly modified technical definitions when applied to divinity. Failure to realize this will lead to failure to understand the analogical way in which personhood is applied to God.

A4: Aquinas leaves the hardest problem until last! How are we to understand personhood when it is applied to God? How does the analogy with created personhood work? The fundamental problem lies with our use of the word “person” in everyday language: when I talk about “that person, John”, I am referring to a concrete individual, to a primary substance. When I talk about a “group of people”, I am pointing to a plurality of individuals; the concept of relation doesn’t seem to enter into view at this point. Aquinas recognizes this and recalls that some theologians (including St. Augustine) took the word “person” as signifying the essence in God. They took the relational aspects defined by conciliar decree as a sort of ad-hoc “add-on” intended to confute heretics. Aquinas is not satisfied with this explanation, arguing that it simply leaves the door wide open for further misconceptions.

Another way of looking at the use of the word “person” when applied to God is to consider that it simultaneously points to both substance and to relation. The question remains as to which is primary: does “person” signify substance primarily and relation indirectly, or does it signify relation primarily and substance indirectly? Aquinas is happy with neither of these approaches but affirms that the second is closer to the truth; still, more work needs to be done.

To do this, Aquinas notes that we have to distinguish between what we signify when we talk about a “human person” (“this flesh and these bones and this soul which are the principles that individuate a man”) and what we signify when we talk about a “divine person”. When we talk about divinity, we remember that there are no accidents in God: the divine relations subsist in exactly the same way that the divine essence subsists. Therefore Divine Paternity (relation) is God the Father (person) is divinity (essence). Therefore, “divine person” signifies a relation as subsistent. For Aquinas, when we are talking about divine personhood, relation and essence are tightly interwoven and although we might assign priority to one, we have to remember that such identification is wrapped around with provisos.

So, Aquinas notes that his solution is, in a sense, consistent with the two previous ideas about relation and essence suggested above. However, it is important to note that he has welded the two ideas of relation and essence together much more closely than the previous theological solution would have it. It is true that “person” signifies relation directly and essence indirectly but we must note that it signifies “relation” as an hypostatis when we are talking about divinity. Similarly, it is correct to say that “person” signifies essence directly and relation indirectly but we must remember the proviso that this is insofar as hypostasis and essence coincide.

Handy Concepts

  • Aquinas adopts the definition of Boethius: “The person is an individual substance of a rational nature”. It’s a good definition from his point of view as it is (i) accurate and (ii) amenable to a strategy of analogical predication.
  • Individuals are characterized by their self subsistent existence. They are also characterized by the property of incommunicability.
  • It is important to grasp the technical meaning of the terms used in Trinitarian theology and to recognize that their analogical use when applied to divinity can mislead us if we are not careful.
  • Personhood in God corresponds to subsistent relation. Later on we will see that, in a sense, we should say that God is Father not because he has brought forth a Son; rather He has brought forth a Son because He is Father.
  • In article 4 Aquinas challenges St Augustine and corrects him. It’s interesting to note the way in which he does this: he has the confidence to take on an argument of one of the greatest of the Church Fathers but he also has the humility to do this is in a very gentle way. Augustine is correct insofar as he is using the theological language available to him, but Aquinas sees the need, and has the ability, to develop what the saint has done. This is a recurring pattern in Aquinas’s work.