Reading St. Thomas: A beginner’s guide to the articulus

Most of the things that Thomas deals with whether by way of the question or other methods are quite complicated. But Thomas sees no point in making complicated matters more complicated.

Detail from "Saint Thomas Aquinas" (1605) by Adam Elsheimer []

Reading St. Thomas for the first time can be a challenge. Besides his scholastic vocabulary, another stumbling block for you might be the literary form of his writing. Many of his texts are divided into quaestiones or “questions,” which are in turn divided into articuli or “articles.” This is how Thomas structures his Summa theologiae, for example. Although the comparison isn’t exact (and the reason why will become clear later), as a first approximation you might think of questions as functioning like chapters and of articles as functioning like the sections of a chapter. Each question focuses on a particular topic and each article discusses an issue connected to that topic. For instance, the tenth question of the first part of the Summa is on God and eternity and the second article of this question considers whether God is eternal.

So far so good. But once we get into an article the different parts into which it is organized might cause some bewilderment. Why this arrangement? How do these different parts relate to each other? Let’s see if we can sort these things out.

An article from St. Thomas’s Summa theologiae

I will start with a word about citation conventions and abbreviations. It is common to use “q.” as the abbreviation for a single question and “qq.” for several questions. Similarly, it is common to use “a.” as the abbreviation for a single article and by “aa.” for several articles.

I should also note another convention, one which is used in citations of the Summa theologiae. The Summa is divided into three parts. The second part is further divided into two parts: the first part of the second part and the second part of the second part. It is common to refer to these parts of the Summa by this set of Roman numerals: I, I-II, II-II, III. So, the first article of the first question of the first part of the Summa would be cited thus: Summa theologiae, I, q. 1, a. 1.

To give us an example to work with in our look at the Thomistic article I am going to take one of the shorter articles from the Summa: I, q. 10, a. 2. This is the one on God’s eternity that I just mentioned.

Here it is:

Article 2i

Whether God is eternal

Here are the arguments of the second article.ii It seems that God is not eternal.

Objection 1. Nothing that is made can be said of God. But eternity is something that is made. Thus, Boethius says that “the now that flows makes time, the now that stands still makes eternity.” And Augustine says in the book Octoginta trium Quaest. that “God is the author of eternity.” Therefore, God is not eternal.

Objection 2. Furthermore, what is before eternity and after eternity is not measured by eternity. But God is before eternity, as is said in the book de Causis. And Exodus, 15 tells us that God is after eternity: “The Lord will reign for eternity and beyond.” Therefore, to be eternal does not belong to God.

Objection 3. Furthermore, eternity is a kind of measure. But to be measured does not belong to God. Therefore, it does not belong to him to be eternal.

Objection 4. Furthermore, in eternity, there is no present, past, or future since it is simultaneously whole, as was said [in the previous article]. But in Scripture words denoting present, past, and future time are said of God. Therefore, God is not eternal.

On the contrary there is what Athanasius says: “The Father is eternal, the Son is eternal, the Holy Spirit is eternal.”

I answer that the concept of eternity follows from immutability, as the concept of time follows from motion, as is clear from what was said [in the previous article]. Hence, because God is maximally immutable, being eternal maximally belongs to him. Nor is he eternal only, rather, he is his eternity, whereas nothing else is its duration since nothing else is its being. But God is wholly his being; hence, as he is his essence, so he is his eternity.

Reply to Objection 1. The now that stands still is said to make eternity according to our apprehension. As the apprehension of time is caused in us by the fact that we apprehend the flow of the now, so the apprehension of eternity is caused in us by our apprehending the now that stands still. When Augustine says that “God is the author of eternity” this is to be understood of participated eternity. For God communicates his eternity to some just as he communicates his immutability.

Reply to Objection 2. From this the answer to the second objection is clear. For God is said to be before eternity, according as it is participated by immaterial substances. Hence, it is also said in the de Causis that “intelligence is equal to eternity.” Moreover, when it is said in Exodus that “the Lord will reign for eternity and beyond,” “eternity” means an “age,” as another translation has it. Thus, it is said that [the Lord] will reign beyond eternity, because he endures beyond every age, that is, beyond every kind of duration. An age is nothing more than the period of each thing, as is said in the first book of de Coelo. Reigning beyond eternity can also be taken to mean that if any other thing were supposed to exist forever (like the movement of the heavens, according to some philosophers), then God would still reign beyond it insofar as his reign is simultaneously whole.

Reply to Objection 3. Eternity is nothing other than but God himself. Hence, God is not called eternal as if he were in any way measured; but the concept of measurement is there understood only according to our apprehension.

Reply to Objection 4. Words denoting different times are applied to God insofar as his eternity includes all times, not as if he himself were altered through present, past, and future.


Like the other articles in the Summa, this article has a title that states its topic: “Whether God is eternal.” The Latin is: Utrum Deus sit aeternus. The Latin word utrum is the common first word in the title of Thomas’s articles in the Summa. It can be translated as “whether.” As Giordano Ghini explains, the “whether” is meant to signal a question to which the answer is yes or no.iii So, we might rephrase the title of q. 10, a. 2 thus: “Is God eternal?”


In this part of the article Thomas states a set of arguments whose conclusions are usually opposed to the conclusion he will come to. Sometimes these arguments are attributed to a particular author or text and sometimes no author or text is given. Thomas is not stating his own views in the objections. In the Latin text the objections are often introduced by the phrase Videtur quod, that is, “It seems that.” In q. 10, a. 2 the objections are introduced with this line: “It seems that God is not eternal.”

On the contrary

Next, Thomas states an answer to the question under discussion that opposes the conclusions of the objections and is usually in agreement with his own conclusion. In the Latin text this part is introduced with the phrase Sed contra, which is a phrase that is now regularly used by English-speakers and means “On the contrary.” In our example the text of the Sed contra is taken from St. Athanasius, who in his creed affirms the eternity of all the persons of the Trinity.

I answer that

It is only in this third part of the article that we first have Thomas speaking for himself. In Latin this section begins with the words Respondeo dicendum quod, which English translators typically render as “I answer that” but which could also be rendered as “I answer that it must be said that.” This part of the article is also called the corpus articuli or the “body of the article.” Here Thomas offers his answer to the question under discussion, giving his reasons for the conclusion that he comes to. Looking at our example, we can see that, against the objections, Thomas insists that God is eternal. He connects this with God’s immutability or changelessness. Thomas regards time as the measure of change. If God does not change (and Thomas has already argued in q. 9, a. 1 that he does not), then he is not subject to time and is, therefore, eternal.

Replies to objections

Here Thomas replies directly to the objections from the beginning of the article. These replies begin with the Latin word ad, which means “to,” and this is followed by the number of the objection: Ad primum = “To the first”; Ad secundum = “To the second”; etc. In this part Thomas is again presenting his own views. It is important to note that Thomas does not always oppose the objections. There are some articles in which he grants one or more of them.iv When it comes to objections whose conclusions he rejects, Thomas will address their premises in his reply. He often does not bother showing again why their conclusion itself must be false since that is already dealt with by him in the Respondeo. Take his reply to the third objection in our example. He does not address its false conclusion (according to which God is not eternal) but explains the problem with the premise that states that eternity is a measure. As F.A. Blanche points out, Thomas often observes that the problem with a premise has to do with a distinction that the objection fails to make.v We see this in his reply to the third objection too. The objection does not distinguish between different ways of understanding eternity, namely, as a kind of measure and as lacking measure.

A little historical background

The format that Thomas adopts in his articles is one that was common in medieval academic writing. It was called the quaestio or “question.” This may provoke confusion given my earlier distinction between questions and articles. A question, in the technical sense it came to have in the Middle Ages, is a structured way of inquiring about reality. An article exhibits this structure. An article, then, is just a particular instance of employing the question-method of inquiry. A question as a literary unit in a work like the Summa would, on this understanding, be a grouping of these instances of the employment of the question-method that are thematically connected.

Some historians see medieval academic commentary on the Bible as the origin of the quaestio as Thomas knew it. Difficulties in exegesis caused commentators to raise and try to answer questions about the text. Later, questions were pursued independently of biblical exegesis. Here is how Jean-Pierre Torrell sums up the development of the quaestio:

Its origins can be found in the middle of the twelfth century with authors such as Robert of Melun and Odo of Soissons. Initially, the Question simply took the form of a slightly fuller development within the context of the commentary on the Bible with respect to a given difficulty: “Here a question can be raised” (Hic oritur quaestio). Toward the end of the century, with Simon of Tournai, the Question became a scholarly exercise in itself and took the place of a Master’s lecture. At the very beginning of the thirteenth century, we have the Questions of Stephen Langton. But the definitive appearance of this genre in the university did not occur until between 1215 and 1231. The Question quickly took the form of a regular

From Torrell’s account you can see that the quaestio was not only a literary form. It was also an activity carried out in the classroom and in other more public settings.

The way of the quaestio

Some people may believe that the quaestio tends to simplify in an unwarranted way matters that are truly quite complicated. Do we really think that we can deal with God’s eternity in the very neat way that Thomas does in q. 10, a. 2? Catherine Pickstock thinks that people who raise this objection are deceived by appearances.

Only superficially is he clear, but on analysis one discovers that he does not offer us a decently confined “Anglo-Saxon” lucidity, but rather the intense light of Naples and Paris which is ultimately invisible in its very radiance – rendering the wisest of us, for Aquinas after Aristotle, like owls blinking in the noonday. Of course it is true that Aquinas does indeed refute shaky positions with supreme economy, simplicity and clarity of argumentation, but the arcanum of his teaching lies not here. It resides rather in the positions he does affirm, often briefly and like a residue, akin to Sherlock Holmes’s last remaining solution, which must be accepted in all its implausibility, when other solutions have been shown to be simply impossible.vii

I think Pickstock has an important point to make but I would put it differently. Most of the things that Thomas deals with whether by way of the question or other methods are, indeed, quite complicated. But Thomas sees no point in making complicated matters more complicated. So, he prefers to be straightforward rather than allusive and to proceed in his discussions in a clear and orderly way rather than in an obscure and random one. Thomas does not want to add to the darkness but to bring illumination instead. Let’s also remember that in a text like the Summa Thomas’s arguments in later articles usually assume arguments he has made in previous articles. Thus, the argument he makes about God’s eternity in q. 10, a. 2 is part of a long chain of reasoning that was initiated in q. 2. What you get in an individual article in that case is just the tip of the iceberg, so to speak.

But people might also be put off by what they see as the artificiality and rigidity of the question. Our encounter with and thinking about reality, they might tell us, is not so formulaic but more lively and free. Such people might, in this respect, point to the superiority of the Platonic dialogue or the Cartesian meditation or the Marcellian journal. These forms bring us closer to “lived experience,” or so they might urge.

Josef Pieper suggests that, in fact, the question is very near to the first of the above-named literary forms, the Platonic dialogue.

At bottom the scholastic articulus is quite close to the Platonic dialogue. And if we would think of the scholastic articulus brushed clean of the dust of the past, we would find it, I think, an exciting affair. Let us take a contemporary problem that concerns us and formulate it as a question. Then, in the most precise and concise language, the difficulties are presented – the real weighty counter arguments. Then comes the clear, ordered exposition of the answer. Finally, on the basis of this systematically developed answer, there follows an exact reply to the counter-arguments. And all this is compressed into one or two printed pages – that being the typical length of a scholastic articulus of the great period. “No writers have ever said more with a stricter economy of words,” says Gilson. It would be difficult to conceive of a livelier form – and any that makes greater intellectual demands on the writer!viii

Yes, you could view the question as a formalized dialogue. We hear from one group of participants in the objections, from another in the Sed contra, and then in the corpus and the replies to the objections we hear from the main character. The difference is that the question cuts out all the fat, that is, whatever seems to be superfluous to the matter we are dealing with. We are not informed, as we are by Plato, about the anger welling up in Thrasymachus over Socrates’s account of justice or about the concern of Socrates’s friends as the hour draws near when he must drink the hemlock. The question does not bother with such things but sticks single-mindedly to the task of determining the truth of the matter under discussion.

These considerations may or may not help us to warm up to the scholastic quaestio. Whether they do or not, there is a further point to emphasize. In a question the author’s interest is not in giving us a history of his ideas. His interest is in offering a rational justification for affirming or denying some proposition (e.g., “God is eternal”). He regards the various personal circumstances that are connected to our discovery of some truth as irrelevant to this purpose. Suppose it was not until I read Thomas that I came to understand why it makes sense to attribute eternity to God. And suppose that I read what Thomas says about God’s eternity while on a train from Paris to Milan, downing three martinis in the process. If I want to show you that God must be eternal, none of these facts will supply the proof necessary to do that. They won’t even figure as a part of the proof. They are not the reasons that God is eternal. They are historical facts about me that, in themselves, have nothing to do with God’s eternity. They might add color to my intellectual autobiography but if I am constructing a quaestio about God’s eternity, I will not include them. What I will focus on rather will be the nature of eternity and the nature of God and how the two are connected.

Last words

Of course, the quaestio is not the only literary form that Thomas uses to express himself but it is an important one. If you want to work your way profitably through the Summa, the commentary on Peter Lombard’s Sentences, the De veritate, or the De potentia, among other texts, then you need to understand it. I hope I have helped you to do that here.

I mentioned at the start that Thomas’s vocabulary can be one of the problems for first-time readers. In a future installment of “St. Thomas for Today” I will offer you a glossary of some of Thomas’s key terms. There are a lot of books that contain such glossaries but many of them are geared towards people who know Thomas fairly well or have a philosophical background. I will try to do something that is more accessible to beginners.


i Leonine edition, vol. IV, p. 96. The translation is my own.

ii The Latin is: Ad secundum sic proceditur. After the title the phrase Ad…sic proceditur typically follows. It is standardly translated in English as “We…proceed thus.” I propose an alternative translation following a suggestion of F.A. Blanche. See his “Le vocabulaire de l’argumentation et la structure de l’article dans les ouvrages de saint Thomas,” Revue des Sciences Philosophiques et Théologiques 14 (1925): 172-177.

iii S. Tommaso d’Aquino: La Somma teologica: Introduzione generale (Firenze: Adriano Salani, 1949), p. 262.

iv See, for example, his reply to the third objection in Summa theologiae, I-II, q. 93, a. 4.

v “Le vocabulaire de l’argumentation et la structure de l’article dans les ouvrages de saint Thomas,” 185-186.

vi Aquinas’s Summa: Background, Structure, and Reception, B.M. Guevin, trans. (Washington, D.C.: Catholic University of America Press, 2005), p. 65. John Marenbon disputes this standard history of the quaestio. See “Method” in The Cambridge Companion to the Summa Theologiae, P. McCosker and D. Turner, eds. (Cambridge: Cambridge University Press, 2016), pp. 76-78.

vii Truth in Aquinas (London: Routledge, 2001), pp. 20-21.

viii Guide to Thomas Aquinas, Richard and Clara Winston, trans. (New York: Mentor-Omega Books, 1962), p. 76.

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About Joseph G. Trabbic 15 Articles
Joseph G. Trabbic is Associate Professor of Philosophy at Ave Maria University. He has published in various academic journals, including Religious Studies, International Journal of Philosophy and Theology, and New Blackfriars. He is also a contributor to


  1. This is one valuable exposition (!), especially to this reader whose familiarity is mostly limited to secondary sources…

    The value of lost clarification is SALIENT TODAY in two raging examples: (1) the coherence of faith and reason (science), and (2) the irreducible reality of both the solar system and the preborn child, irrespective of relative physical size…

    FIRST, 13th century Aquinas’ open-minded (!) theology and the 16th century Galileo incident:

    “Reasoning is employed not as furnishing sufficient proof of a principle but as showing how the remaining effects are in harmony with an already posited principle; as in astronomy the theory of eccentrics and epicycles [the Ptolemaic universe with the sun and planets rotating around a stationary earth] is considered as established because thereby the sensible appearances of the heavenly movements can be explained; NOT however as if this proof were sufficient, since some other theory [Galileo’s telescope disclosing the sun at the center] might explain them [!]” (Summa Theologica, I, 32, I, ad 2; cited in L.M. Regis, Epistemology, 1959, p. 455).

    SECOND, regarding science and both Galileo’s seeing truly the external “universe” and today’s closed-minded (!) courtroom blindness/spiritual darkness to internal “universes,” now even enabling infanticide:

    The scientific parallel is between Galileo’s telescope and today’s ultrasound and embryology. Galileo’s whispered, “Eppur si muove: Nevertheless, it moves” (then the earth around the sun, and now the preborn child within the mother). His under-the-breath protest prefigures today’s ultrasound “Silent Scream” of the breathless and aborted.

    The post-modern “Dark Ages.”

  2. At the beginning of the Summa St Thomas Aquinas’ first premise is that the only absolute truth is the existence of God. All else although there are truths that are absolute in context, are conditional due to dependence on God. Good point then on God’s eternity. Although Aquinas’ proofs as correctly said are not actual reasons why God is eternal, rather as you suggest they are reasons for our understanding that he is eternal. A suggestion if I may to simplify the format, at the Angelicum I used the following. ST 10, 2 Ad 3. Meaning Question 10 Article 2 and Reply to objection 3. Reference to the Responsio would be 10 2. The sequence used by Aquinas in writing the Summa is the sequence used when lecturing to students at the U of Paris. It consisted of a panel thought to be modelled on Plato’s Socratic dialogues, as perhaps alluded to when quoting Jean-Pierre Torrell summing up the development of the quaestio. Logical numerical sequence facilitated notation for memorization since redaction of a lecture was virtually impossible. Memory was far more engaged at the time and important for comprehension. Unlike today’s dependence on immediately accessed electronic data. And the use of Latin as some scholars believe trained the intellect. This presentation on a beginners guide to reading Aquinas is excellent. Without exaggeration I would have greatly benefited to have had it when I began my studies, since it took me a lengthy period to follow Aquinas clearly.

  3. Nice Summary!

    I begin any lecture or class on Thomas with this kind of overview (otherwise, the readers are utterly lost).

    Very good point about the formalization of the Platonic dialogue; you can luxuriate in a dialog form if you have unlimited time to consider and revisit a set of questions, as Anselm did in his monastic school, but if you’ve got to cover a set number of topics in a fixed length of time, you’ve got to cut out the extraneous material and get right to the bones of the issue.

    I am glad you gave the caution that the Sed Contra is not always just the position that Thomas is going to take. This is obvious in those instances when he replies to the Sed Contra explicitly, but it is usually in the Respondeo that he presents the qualification in light of which the Sed Contra is correct.

    One thing to note is that, in the classroom disputations, the Objections and the Sed Contrae were the responsibility of the *students*, to produce a valid syllogism rooted in a true statement enunciated by a recognized authority. The major and the minor are explicitly identified in later developments of the transcriptions of Disputations (14th-cent. and later). Only when you have two sets of syllogistic arguments (the best translation of “objectiones”) arriving, in response to a given question, at both “Yes” *and* “No”, do you have a question worth resolving.

    The Summa Theologiae, in accord with its name, is a Summary version of the classroom exercise of disputation, and frequently you can trace the condensed version in the Summa back to the actual non-condensed classroom exercise of a disputation that we may have record of in his published Disputed Questions on various topics. In those versions, the argument will ping-pong back and forth between arguments on one side and arguments “sed dicebat” in response, which will generate a new thread of argument, to which there is a further response, and so on, giving perhaps five sets of opposed arguments on various points of a given topic, before Thomas steps in to give his determination. Unfortunately this dynamic is often lost in the way the objections are edited.

    Thanks you once again for this overview!

  4. Thank you, Mr. Trabbic. I find your article very useful! I have been trying to study St Thomas Aquinas for about a year now, and you article “organizes” the Summa much better for my understanding. I will be looking forward to your Glossary List. I have been trying to accumulate one of my own but also find that difficult. Thank you so much!

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