On the Alleged Theopaschitism of Peter of Ireland

It has been alleged that Peter of Ireland denied divine simplicity – or, in other words, that he affirmed that there are in God passions, change, and movement. Yet another way to specify the charges is to say that he was a theopaschite – one who believes that God can have “passions” in himself, where “passion” may be defined as suffering, or more broadly as susceptibility to change by outside influence, or even more broadly as any potentiality in search of actualization. What follows is a ridiculously in-depth investigation into this question, seeking to make the relevant sources easily available to anyone who may be interested.

An allegation of theopaschitism against a 13th century university master is certainly noteworthy. When one embarks on a historical survey of the theologians of the pre-modern church, asking them the questions, “Does God have a body?,” “Does God change?,” and “Does God have passions?,” their answer seems unanimously negative. God is absolutely simple, without either division into parts or undeveloped potencies; he is without change, unmoved while he moves all things: do not all theologians say so? At least before the rise of Socinianism in the 16th and 17th centuries augured a rising tide of Enlightenment theology against such traditional concepts? But since such doctrines are so controversial among professing Christians in our times, it is in the interests of fairness to ask: Is it really so unanimous as all that? Was there no minority report on these issues in days of old? Or is it that to reject these doctrines is simply to be modern and radical, while to accept them is to be traditional and orthodox?

I have long been interested in this question. Though a proponent of the traditional doctrines, I have sought out the minority report as a way to gauge how solid these doctrines really are in the tradition. And the conclusion I have come to is that these doctrines really are near-unanimous before the modern period (with the necessary qualification that I have not read everything). Of course, Christian theologians accuse each other of endangering divine simplicity all the time, but this is often a polemical move in fact motivated by their common commitment to simplicity. So widely accepted is the doctrine, that an opponent’s view can be disproven merely by showing that it implies the falsity of divine simplicity. So it is with both sides in the Arian controversy: Eunomius presents himself as a champion of the simplicity of the Father, which he takes the doctrine of homoousios to endanger. Meanwhile, the Cappadocians on the other side argue that the simplicity of the Father is in danger if the Son is not consubstantial with him – indeed, the Council of Nicea had already anathematized any who say that the Son of God is “changeable” alongside those who call him “created.”

Likewise with the Christological controversies: charges of confusing, mixing, and converting the divinity and humanity are frequently lobbed at views emphasizing the unity of Christ, with the implication that such views must be wrong since they endanger the immutability of the divine essence. But such accusations are typically met with vigorous denials that any such implication actually follows, as both sides seek to outdo one another in lauding the immutability, impassibility, and simplicity of the divine essence.

A similar dynamic is at play on the more detailed later end of doctrinal formulation – if Thomas Aquinas and Duns Scotus and Gregory Palamas formulate the doctrine of divine simplicity differently (though all accepting it), and if we hear their advocates accuse one another of endangering divine simplicity, is this evidence for a diversity of opinion on the issue? Or would we do better to follow others who emphasize the great many things they all agree upon, so that these theologians in fact evidence a broad agreement on the doctrine? They cannot be evidence of doctrinal diversity except on the points of detailed formulation over which they actually disagree. In the end, there are many alleged theopaschites in the history of the church – but is anyone actually guilty of the charge?

It is true that if we look early enough we find interesting exceptions. Lactantius advances his own version of divine impassibility against the Stoic version - while he denies need, fear, and pain in God, he affirms anger as a movement in God’s mind in a way that is at odds with later traditionLactantius, On the Anger of God. Gregory Thaumaturgus holds that in the incarnation, the impassible God entered into human passions, only to make the passions suffer rather than suffering himself, so that his impassbility was demonstrated in his passions – suffice it to say that this view is a little hard to place in the context of later debatesGregory Thaumaturgus, To Theopompus.

On top of this, we may also wonder about those who are not theologians – what about the common Christian? Is their theology so subtle? John Cassian tells us of a monk who wept when he finally accepted that God did not have a body, thus losing the image of God he relied upon in prayerCassian, Conferences 10.3. Here too we must be careful though – the picture of the simple, ignorant monk holding on to superstitious beliefs about God may be all too convenient. The Anthropomorphite Controversy of 399 AD in Egypt is another example of an event where it is hard to distinguish actual theological viewpoints from how they have been represented in polemiccf. Paul A. Patterson, Visions of Christ.

As I mentioned before, Christology furnishes many ambiguous examples. Cyril’s formula “The Word of God suffered in the flesh” Cyril, The Twelve Anathemas, Council of Ephesus 431 AD is his attempt to defend the unity of the God-man in his suffering, and not a denial of divine impassibility, as he affirms in his letter to John of Antioch. Likewise with the so-called ‘theopaschite formula’ proposed by the Scythian monks: “one of the Trinity suffered.” This was an attempt to preserve this Cyrillian emphasis within a Chalcedonian Christology, and this language was approved – when rightly understood – by the Second Council of Constantinople in 553 ADcf. Price, The Acts of the Council of Constantinople of 553, p.9. Those who have perused the minutes of this council know how strongly those gathered there supported divine impassibility!

My list of outliers for this doctrine is thus very short. But I am always interested in expanding it – I have not, after all, read everything! So it was with great interest that I observed the claim that one Peter of Ireland – said to be a teacher of no less than Thomas Aquinas – denied divine simplicity.

Who was this Peter of Ireland? The introductory works I was able to findcf. Dunne, Peter of Ireland, the University of Naples and Thomas Aquinas’ Early Education gave me a Peter of Ireland who taught natural philosophy, with surviving works on natural philosopy and logic, but not theology. Furthermore, while some allege he taught Thomas, the matter is disputed.

So what was the source for Peter’s views on divine simplicity? The citation I turned up was: Giuseppe Sermoneta, Un Glossario Filosofico Ebraico Italiano del XIII Secolo (Olschki Editori: 1969), p.45n. This source was available at my local university library, but turned out not to be the primary source. Rather, it included the following quotation in a footnote (my own translation of the Italian follows):

già riconobbe il Maestro Petro de Bernia che i cristiani nel credere che la Divinità si sia incarnata accettano la necessaria conclusione, aver il Nome subito passione, movimento e mutamento.Sermoneta, Un Glossario Filosofico Ebraico-Italiano Del XIII Secolo, p.45

Master Peter of Ireland already acknowledged that Christians, in believing that the Divinity was incarnate, accept the necessary conclusion, that the Name has undergone passion, movement and change.

As we will see, this is a fair translation, though not beyond challenge on some points. The source cited is an edition of a Hebrew-Italian glossary by Moses ben Solomon of Salerno, but the quote itself is cited from another work by the same author, his Ṭaˤănôt or Objections, a polemic against Christian doctrine. Two points may already be made: First, this is not a quotation of Peter of Ireland himself, but a representation of his views by an opponent in a polemical context. I am not an expert in history or historiography, but I do have some interdisciplinary training in the subject, and it was hammered into me that one should not uncritically accept a polemical characterization of someone’s view. Furthermore, the reported view applies specifically to the doctrine of the incarnation: it is not a statement about God’s passibilty per se but a statement about what the incarnation in particular implies. What was said above applies here: Christology is fertile ground for unfounded allegations of theopaschitism.

This is already good reason to dismiss the quote as evidence that Peter of Ireland denied divine simplicity. I thought about calling a halt to my inquiry here. The actual primary publication for the Objections was a 1932 dissertation by Stanislaus Simon, Mose ben Salomo von Salerno und seine philosophischen Auseinandersetzungen mit den Lehren des Christentums. I knew this would be a little difficult to acquire, as the political situation in the District of Columbia has made it impossible for independent scholars to access interlibrary loans through District libraries. On the other hand, pushing the fact-check forward to the next level sounded like a fun challenge, which would require me make an attempt at Medieval Hebrew and follow up with Latin. I realized that some who might be interested in the topic would have difficulty dealing with the sources, and might appreciate a clean presentation. So with the help of a friend, I acquired a copy of the primary source and went further down the rabbit hole.

What follows is a presentation of the quote of Peter of Ireland in Moses of Salerno’s Objections, together with the surrounding context. In the broader context, Moses is raising objections to the doctrine of the incarnation, and responding to various Christians attempts to answer these objections. The general theme of these objections is that God could not have become incarnate without some change in God. The following paragraphs occur on folios 246a-b of the manuscript – some philological notes follow.

וכבר נתבוררתי מהם כי לא יודע אצלם קבלת הבשר איך היתה רק מה שאמרת לקבל' הבשר אינה שנוי כי לא ירד האלהות לקבל הבשר רק הבשר נתעלה ונדבק אל האלהות והשנוי לא היה בו כי אם בשר כל זה איננו שוה כי נמצא לפי דבריך שהאלהות קבל' הפעלות ר"ל שאעפ"י שתאמ' שאלהות לא נשתנה כי אם הבשר הוא שנתעלה ונתקרב אל ה' אעפ"כ לא יועיל לך מאומה כי עם כל זה יהיה הדבר שנוי אחר שיש בו להיות אחד הבשר והאלהות - הפעלות פסיאוני בלעז - חלילה חלילה מה שלא יאות בשם חלילה.Simon, Mose ben Salomo von Salerno und seine philosophischen Auseinandersetzungen mit den Lehren des Christentums, iv lines 8-24

Already I have made it clear from them that their side does not know how the assumption of the flesh happened. But what you say about the assumption of the flesh, that it is not a change because the divinity did not come down to receive the flesh, but the flesh was taken up and united to the divinity, and the change was not in him but the flesh – all this avails nothing. For it follows according to your words that the divinity assumed passivity, that is, although you say that the divinity was not changed, but it was the flesh that was taken up and brought near to Hashem, even this will profit you nothing, for with all this the event would be a change, since the flesh and the divinity were able to become one – a passivity – "passione" in foreign speech – which does not befit Hashem.

וכבר הודה אלי החכם פיטרו דבירביאה ואמ' כי בהאמין הנוצרי שהאלהות קבלה גשם יבאו לשים אל ה' הפעלות ותנועה ושנוי מה שאין בו חס ושלום. ואם תאמ' שגם גשם האלהות לא היה הפעלות בהתקרב הבשר אליו כי לא נשתנה בעצמו דבר, הנה מצד הבשר יש שנוי ומצד האלהות אין שנוי א"כ קבלת הבשר אין כלום אחרי שאין דבוק שהרי אתה אומ' שהבשר והאלהות לא נתחייבו להיות אחד ונמצא שאותו האיש היה אדם ולא אל וגופו בשר ולא רוח ואתם שמאמינים בו תאמינו לרוח כי לא נמצא בו רק מה שנמצא בשאר הנבראים כי לא בהתקרב האדם אל המלך הוא מלך ולא בן המלך וקריבת אלהים אינה כי אם קריבת מדע.

The sage Peter of Ireland once informed me that when Christians believe that the divinity assumed a body, they come to impute to Hashem passivity, movement, and change, which are not in him, heaven forfend. But if you say that even the body of the divinity was not a passivity when the flesh drew near to him, for nothing in his substance was changed, then from the side of the flesh there is change, but from the side of the divinity there is not change: if so, there is no taking on flesh at all, since there is no joining. For you say that the flesh and the divinity are not one by necessity, and it follows that the same man was a human and not God, and his body flesh and not spirit. And you who believe in him believe in the wind, for there exists in him nothing but what exists in whatever else is created. For when a human is brought near to the king, he is not the king nor the son of the king. And there is no approach to God except the approach of knowledge.

The first paragraph here, preceding the reference to Peter of Ireland, advances against the incarnation the argument that if God assumed flesh, then his divinity would be changeable and passible. It begins with a jab at the doctrine of the ineffability of the incarnation – Christians admit they don’t know how it happened. But if God was at one moment not joined to the flesh, then joined to it at the next, would this not be a change in God?

This was a long-standing question in Christian theology and a point of discussion in the medieval schools. It had long been traditional to assert that the incarnation involved no change in God.cf. Athanasius, On the Incarnation 17.5 Moses of Salerno trots out a contemporary elaboration of this tradition: it is not the divinity that changes in the union, but the flesh which changes in being assumed. So far as I can tell, this argument was developed for the first time in the 13th century – one thinks of Aquinas, but Walter H. Principe identifies this position also in Alexander of Hales, Hugh of Saint-Cher, and Philip the ChancellorAquinas, ST III Q2 A7, Q16 A6, and Sentences III D1 Q1 A1 ad1; Principe, The Theology of the Hypostatic Union in the 13th Century, vol.4, pp.198-199.

Moses is not satisfied with this answer – both human and divine natures would be involved in the change, and both would have to be able to be united to the other. But this ability to be united would be a passion – a potency or potentiality which was actualized in the union. But then the divine nature would be subject to passion. Moses, along with Christian theologians of the time, would have been aware that Aristotle in book 12 of his Metaphysics taught that as the first cause, God must have actuality as his very being, without any potentiality at all. He is thus putting a fine Aristotelian point on the old problem of how to safeguard divine immutability and impassibility in the incarnation.

From here, we come to the quote itself: “The sage Peter of Ireland once informed me that when Christians believe that the divinity assumed a body, they come to impute to Hashem passivity, movement, and change, which are not in him, heaven forfend.” Notice that in the quotation by Sermoneta, the last two clauses are cut off: “which are not in him, heaven forfend.” Presumably, this is because Sermoneta suspects these words switch from Peter’s viewpoint to that of Moses of Salerno. This is possible, but not the only possible interpretation. As for the first of these clauses, “which are not in him,” it is possible that on Peter’s view, the passivity, movement, and change which Christians “impute” to God are nevertheless somehow not “in him,” and the quote records both emphases. As for the second of these clauses, one might suppose that the phrase I have translated “heaven forfend” – the Hebrew idiom ḥas wǝšālôm – cannot describe Peter’s view precisely because it is a Hebrew idiom. But this would be an incorrect assumption – the same idiom actually begins reported speech by Christians elsewhere (cf. ii line 21). Apparently, Moses of Salerno was comfortable translating his opponents into idiomatic Hebrew.

If the whole line were attributed to Peter of Ireland, then it would actually be saying that he strongly disapproved of the idea that “passivity, movement, and change” were “in” God, even if Christians “come to impute” them to God in the incarnation. We will return to how those two claims might be made consistent below. For now, I will remark on the difficulty of deciding between these two interpretations. This is a problem for using the quote as evidence for Peter of Ireland’s views – we first have to make interpretive judgments about how Moses of Salerno is representing Peter’s view before we can even start to speculate about whether he represents Peter accurately! Also, note the importance of consulting primary sources - nothing in Sermoneta’s footnote tips a reader off to the judgment call he made in omitting the two missing clauses.

Before we leave the quote itself, we should say something about the idiom yābōˀû lǝśîm, “they come to impute.” I have taken the verb in the Qal stem rather than the Hiphil, though there is a similar idiom in the Hiphil, “you bring to impute” (x line 20) – but the Qal is more likely to receive the defective spelling which the verb has here. This is not an idiom I have been able to identify in Rabbinic or Medieval Hebrew, and I suspect we are to look instead to the influence of Latin impōnō and its use in scholarly discussions of signification. In any case, the other use of the idiom (v line 30) describes an implication to which one can be held despite wishing otherwise – bǝˤal korḥô yābōˀ lǝśîm, “by compulsion he will come to impute…” Furthermore, the example with the Hiphil at x line 20 seems to also involve an implication one would rather avoid, as do a couple similar idioms with bôˀ (albeit with different complementary verbs) in xviii line 9. This puts us squarely in the realm of implication here. We are not talking about something Christians intentionally affirm nor readily admit, but something their belief in the incarnation implies. What about Peter, who is reporting this? Should we take him to be perfectly comfortable with this implication? Or is this a point he was pushed to concede in debate, like the imagined Christian interlocutor at v line 30? Precisely because this is the language of implication, rather than direct affirmation, we can’t assume that this reflects Peter’s considered opinion or preferred formulation. To get any deeper into what Moses of Salerno is claiming Peter said here, we would need to answer the question of how much of the quote he is attributing to Peter, as well as what its function is supposed to be in the wider context.

Let’s turn to that context – what is argued in the rest of the paragraph? Moses of Salerno continues with the topic of whether the assumption of the flesh was itself a passivity in the divine nature – in other words, the topic has not changed from the previous paragraph. He considers a standard 13th century Christian strategy to address the problem – assert that the change was not in the divine substance, but entirely on the side of the flesh. If this is true, he argues, then really there is no union at all. Since the flesh and the divinity are not one by necessity – that is, they are essentially distinct – then the human man is in no way God, but a creature like any other creature. There is no kind of approach to God which could convert a man into God.

So, how does the report from Peter of Ireland fit into this argument? In what precedes, Moses of Salerno argued that the assumption of the flesh requires at least a passivity in the divine nature to be capable of union. If Peter is cited as the conclusion to this line of argument, then the point could be simply that he agrees: Christian belief in the incarnation does in fact imply passivity in God. But according to the paragraph divisions in the text, the citation of Peter instead introduces the next paragraph. If Peter affirms passivity in the divine nature, the quote’s connection with the rest of the paragraph would be a non sequitur, for the next sentence sees Moses arguing that even if he conceded the assumption wasn’t a passivity, this would just mean there wasn’t really a union of divine and human. Why introduce a paragraph where you rhetorically concede the point with a quote of an opponent conceding the point the other way, rather than concluding your previous paragraph arguing against that point? At the very least, it makes for a choppy transition.

But what if we take the quotation by Peter to run through that whole first sentence? Then Peter would be saying that Christian belief in the incarnation implies the imputation to God of a change, passivity, and movement that are not in him. Peter might be saying that these terms can in some way be applied to God even though they are not in him. This attempt to dodge the implication of passivity in God (it is imputed to him, but not in him) would then be the set-up for Moses to swing his argument the other way, and argue on this basis that the incarnation cannot really involve a union with the divine nature. Peter might still be the imagined interlocutor of the following sentence: “But if you say that even the body of the divinity was not a passivity when the flesh drew near to him, for nothing in his substance was changed...” (note the parallel preposition – the change is not in the divine substance). This resolving of terms into language about substances sounds like a Chalcedonian strategy for defending the divine nature from passibility – Peter may simply be saying that terms like passibility may be applied to the Person of the Son, but not his divine nature.

Of course, it would be clarifying if we had the term “person” here in Moses’ report of Peter’s words. Notice though that Moses shifts his terms for God in the middle of the sentence. It is the divinity (hāˀĕlōhût) who assumes a body, but the Name (haššēm) to whom passivity is imputed. Why switch proper nouns? Why not just refer back to “divinity” with a pronoun? Is it possible that Moses is reflecting here a difference in Christian terminology between “God” taken personally (i.e., God the Son or God the Word) and “God” taken as the divinity or divine nature? If Moses’ switch in terminology here reflects his awareness that Peter made a significant terminological distinction here, something along the lines of a Chalcedonian nature/person distinction seems the most likely option in this context. Moses argument would then be: even if the kind of Chalcedonian logic-chopping that Christian scholars like Peter deploy could succeed in showing how God might assume a body without becoming passible, this would have to result in such a thin conception of what “assuming” meant that it would not really count as a true union of the divine nature with the resulting human. Peter would stand in here not as the rare Christian scholar who would concede the charge that the incarnation implied passibility in God, but as a representative of standard Chalcedonian strategies for avoiding this charge.

This is I think the best we can do to understand how Moses of Salerno construes Peter of Ireland’s view on the incarnation and divine simplicity, based on this very short report in a polemical context. But I’m still enjoying my time in the rabbit hole. Is there anything else we can put on the table, from Peter’s own works or his context, that could help us guess what precisely his view would be?

As I mentioned above, Peter’s extant works belong to the subjects of natural philosophy and logic – no work of theology by him is yet known. But that does not mean that theology does not come up incidentally in his works. Here are a couple very pertinent excerpts from his logical work:

non est possibile causam primam intelligere aliquid eorum que sunt hic secundum quod sunt hic; nec est dubitandum quin intelligat et uiuat, cum sit intellectus purus, sicut probatur in naturalibus; intellectus autem purus, qui nullo modo est in potencia, semper intelligit; intelligere autem uiuere est. Et quod intelligat, breuiter patet, quia est essencia abstracta et liberata a materia, et omnis essencia abstracta a materia est intellectus in actu.Expositio Et Quaestiones In Librum Aristotelis Peryermenias Seu De Interpretatione (ed. Michael Dunne), Book 1, Lectio 16, Q.1

It is not possible for the first cause to know any of the things which are here according to what they are here, nor is there any doubt that it knows and lives, since it is a pure intellect, as proven in natural science. A pure intellect, which is no way in potency, knows always, but to know is to live. And what it knows will quickly become clear if one considers that it is an abstract essence and free from matter, and an essence entirely abstract from matter is an intellect in act.

Patet ergo demonstratiue quoniam nichil intelligit extra se; intelligit ergo se solum per se et primo; sua autem essencia semper sibi est presens; ergo semper intelligit, et sunt in eo quod intelligit et quo intelligit et intelligens idem. Et hec est Trinitas personarum, ad cuius cognitionem omnes aspirabant; sua ergo essencia est sua actio, et sua actio est sua uoluntas, set quod sicut agit, semper aget; quod patet demonstratiue, quia si sua actio est sua essencia, essencia autem non separatur a se, quare nec actionem est separare; aut da oppositum: actio separatur et sua actio est sua essencia, ergo sua essencia separatur a se, quod est manifeste inpossibile; non ergo aliquando agit, <aliquando> non, set semper.

Thus it is demonstratively clear that it knows nothing outside itself, therefore it knows itself alone through itself and first. But its essence is always present to it, therefore it always knows, and in it what it knows, and that by which it knows, and knowing are identical. And this is the persons of the Trinity, to the knowledge of whom all aspire. Therefore its essence is its act, and its act is its will. It is that which it acts, acting always, which is demonstratively clear, because if its act is its essence, but its essence is not separate from it, how will you separate the act? Or take the opposite: if the act is separated and its act is its essence, then its essence will be separated from it, which is clearly impossible. Therefore, it does not sometimes act, sometimes not, but it always is.

This is a typical example of the sort of thing which one might vaguely label as “Christian Aristotelianism.” That the first cause has no potency (i.e., potentiality, passibility), that its essence is its act, and that its life and knowledge are identical to this act: all these claims originate from the twelfth book of Aristotle’s Metaphysics. This first cause, Peter assures us, is simply the same thing as the Christian Trinity. Why those who lately have spread rumors of Peter’s theopaschitism have not bothered to read him in his own words, I know not. But this quote sets a baseline for his theology which is quite typical for a 13th century scholar working at a European university – God is impassible, because he is pure act. Incidentally, whether or not Peter of Ireland ever taught Thomas Aquinas, Thomas did use this commentary in his own commentary on Peryerminias.

So God is “no way in potency” for Peter, i.e., he is not passible. But what about the incarnation? If we establish that God must be impassible to be the first cause, how do we explain how he can become man? Regrettably, we don’t have a source from him explaining how to deal with this question. What we can do is look at his contemporaries, to understand the waters he was swimming in.

The issue of whether the assertion “God became flesh” implies change or passibility in God – so important to Moses of Salerno’s argument – received extensive discussion in the 13th century university. It had been addressed in Lombard’s Sentences in the previous century, where it occupied the 6th and 7th distinctions of Book III. We could consult Alexander of Hales, Albertus Magnus, or Thomas Aquinas himself for an account of this. But to keep things simple, I will offer a couple quotations from John of Damascus. John’s work was translated into Latin in the 12th century, and frequently cited by Lombard, as well as these other theologians. He is especially important as the source of the doctrine of the “communication of properties” in Christology. I shall cite him in the Latin translation that would have been familiar to Peter’s contemporaries.

Propter unitionem enim quae est secundum hypostasim caro deificata dicitur, et Deus fieri et homotheos Verbo (id est simul Deus cum Verbo); et Deus Verbum incarnatus esse et homo fieri et creatura dici et "ultimus" vocari; non ut duabus naturis transmutatis in unam naturam compositam: impossibile enim in una natura simul contraria naturalia fieri; sed ut duabus naturis secundum hypostasim unitis, et circumincessionem quae est ad invicem inconfusibilem et intransmutabilem habentibus.De Fide Orthodoxa: Versions of Burgundio and Cerbanus (ed. Buytaert), c.91 (= 4.18), lines 61-69

Because of the uniting which is according to hypostasis, the flesh is said to be deified, and to become God and to be God-equal Word (that is, at the same time God and Word); and the God-Word to be incarnate and to become man and said to be creature and called “last;” not as two natures being transmuted into one composite nature: since it is impossible for natural contraries to come to be at the same time in one nature; but as two natures united according to hypostasis, and having a circumincession which is to one another, inconfusible and intransmutable.

Notice how John deploys the distinction between nature and person (= hypostasis) here. The two natures are not confused or converted into each other. But by virtue of their union in one hypostasis, the properties of one nature can be said of the other. So one can say something like “The God-Word became man” when what one means is that “the God-Word was united to a human nature according to the hypostasis.” Consider also the following quote:

Igitur divinitatem quidem dicentes, non nominamus de ea humanitatis idiomata. Non enim dicimus divinitatem passibilem vel creabilem. Neque autem de carne, scilicet humanitate, praedicamus deitatis idiomata. Non enim dicimus carnem, scilicet humanitatem, increabilem. In hypostasi autem, etsi ex utroque, etsi ex una partium hanc nominamus, utrarumque naturarum idiomata ipsi imponimus. Etenim Christus, qui est quod utrumque, et Deus et homo dicitur, et creabilis et increabilis, et passibilis et impassibilis; et quando ex una partium Deus nominatur et Filius Dei, suscipit ea quae coexistentis naturae idiomata, scilicet carnis, Deus passibilis nominatus et "Dominus gloriae" crucifixus, non secundum quod Deus, sed secundum quod homo idem ipse; et quando homo et Filius hominis nominatur, suscipit ea quae divina substantiae idiomata, et gloriationes, puer proenios (id est ante saecula) et homo anarchos (id est sine principio), non secundum quod puer et homo, sed secundum quod Deus existens proenios (id est ante saecula), factus est in ultimis puer. Et hic est modus retributionis, alterutra natura retribuente alteri quae propria, propter hypostaseos (id est personae) identitatem et eam quae ad invicem circumincessionem. Secundum hoc possumus dicere de Christo: Hic "Deus noster, et super terram visus est", et: Homo hic increabilis est et impassibilis et incircumscriptibilis.De Fide Orthodoxa: Versions of Burgundio and Cerbanus (ed. Buytaert), c.48 (= 3.4), lines 30-51

Therefore speaking of the divinity, we do not name the human properties of it. Nor indeed do we say that the divinity is passible or created. Neither do we predicate divine properties of the flesh (that is, the humanity). Nor indeed do we say that the flesh (that is, the humanity) is uncreated. But in the hypostasis, whether we name it from both or one of the parts, we impute to it the properties of both natures. For Christ (who is that which is both) is said to be both God and man, both created and uncreated, both passible and impassible; and when from one of the parts he is named God and the Son of God, he receives those properties of the co-existent nature (that is, the flesh), being named passible God and crucified “Lord of Glory,” not according as God, but according as the same one is man; and when he is named man and the Son of Man, he receives those properties and glorifications of the divine substance, “Child proaiōnios” (that is, before the world) and “Man anarchos” (that is, without principle), not according as child or man, but according as God existing proaiōnios (that is, before the world) and made a child late in time. And this is the mode of exchange, each nature exchanging to the other those things which are proper on account of the identity of the hypostaseos (that is, the person) and the circumincession which they have to each other. In accordance with this we are able to say of Christ: This is “Our God, and he was seen upon the earth,” and: This man is uncreated and impassible and uncircumscribed.

Properties of each nature are not imputed to the other nature – so though the flesh of Christ is passible, and though Christ is God, we don’t say that the divinity (= divine nature) is passible. However, we do name the properties of both natures in the hypostasis. We can take this so far that we may name the hypostasis from one of the natures, and assign it a property from the other nature. This allows us to justify phrases that sound very theopaschite, such as “passible God” – but what we mean when we say this is “the hypostasis whom we name ‘God’ from his divine nature, we also name ‘passible’ from his human nature.” We can do this because the natures have a mutual “circumincession” or “indwelling” (Greek: perichōrēsis) with each other by virtue of the union.

Note the use of the verb impōnō in the phrase utrarumque naturarum idiomata ipsi imponimus, “we impute to [the hypostasis] the properties of both natures.” This could very well be the verb reflected by Hebrew śîm in Moses of Salerno. Could we say of John of Damascus that he came to impute passivity, change, and movement of the Name, as was said of Peter of Ireland? I think we probably could! Terms like “passible God” are perfectly acceptable as far as John is concerned. And yet his explanation of what those terms mean is precisely designed to prevent the conclusion that the incarnation makes the divine nature passible.

Now, I don’t mean to claim that Peter of Ireland must have shared precisely John of Damascus’ solution to this theological problem. Certainly John was one of the main authorities cited on the issue in Peter’s time. But Alexander of Hales, William of Auxerre, Hugh of Saint-Cher, Philip the Chancellor, Albertus Magnus, and Thomas Aquinas all developed their own solutions with their own peculiar features. There are any number of other distinctions which could have brought Peter to the same place: defending theopaschite-sounding names of God backed up with a Christological grammar designed to shut down properly theopaschite conclusions. My point is that had Peter used John’s categories precisely, Moses of Salerno might easily have written what he did about Peter. Thus, given Peter’s stated commitment to divine impassibility in his own words, Moses characterization of him is not evidence for anything more than the sort of defense of a Chalcedonian model typical of his day. The above discussion hopefully gives the reader a sense of how problematic it is to lift statements out of someone’s Christology and abstract from this directly to their doctrine of God.

So what of the idea that Peter of Ireland, alleged teacher of Thomas Aquinas, denied divine simplicity? It is debunked. The only evidence for this alleged theopaschitism is a report attributed to him by someone else, in a polemical context, concerning his view of the incarnation, in terms perfectly consistent with the Chalcedonian tradition anyway, which must be contextualized against the background of his own explicit affirmation of divine impassibility and simplicity in conventional Aristotelian terms. Whether the reader is looking for a historical precedent to deny the doctrine of divine simplicity today, or simply a theopaschite bad boy for their Thomas Aquinas Bildungsroman, they had better look elsewhere!

I believe my argument for this conclusion is a strong one, but I also have to admit it is a little ridiculous. This is because taking the allegation as seriously as I have here requires one to push quite hard into the precise constructions and discourse function of an exceedingly brief and vague report, and to try to fill in the gaps by reading Latin masters contemporaneous to but distinct from our true target. Perhaps the real lesson here is the wisdom of not relying on a polemical report. If one really insists on doing so, one can try to peer through the polemics to the real person on the other side. But to do so requires one to make so many suppositions one should probably not feel too confident about the result.

Still, this has been a fun side-project for me. I don’t regret the time spent working on medieval Hebrew or 13th century Christology, and I hope I have an excuse to come back to them again soon! And I hope that if anyone does really care about Peter of Ireland’s theology, they will find this exercise helpful in making the sources available.