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.
- 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.