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How to Do Things with Diagrams? A 13th Century Kabbalistic Experiment with a 12th Century Cosmographic Cycle

Jewish Kabbalistic writings often construct elaborate systems to assist their metaphysical speculations on the divine realm. Occasionally, these systems are presented through diagrams that map out the structure of divine potencies and the dynamic relationships between these potencies and the created world. The best-known examples are the numerous variations of thetheosophical Sefirotic Tree, whose branching structure has come to epitomize the dynamic order of divine entities and powers, (sefirot). Yet the early 13th century Kabbalists also drew on other types of geometric diagrams that were readily available in the scientific and theological environments of the time, namely, the concentric spherical diagram as generally informed by Ptolemaic astronomy. These diagrams, which consisted of ten spheres—the 7 traditional planets, the sphere of fixed stars, the diurnal sphere (Primum Mobile), and, in some cases, the Universal Intellect—were integrated and further modified by Jewish theological and Kabbalistic doctrines of creation.

Kabbalistic texts illustrate how dynamic and adaptive these cosmological models were. So much so, that Kabbalists often integrated elements from markedly different systems, mainly theological or cosmogenic, thereby reconstruing the nature, logic, and order of the cosmic diagrams of the time. One notable case appears in Ginnat Egoz (The Garden of the Nut), a cosmic-Kabbalistic work composed in 1274 by the Castilian Kabbalist Joseph Giqatilla. His text includes a spherical diagram that serves as the structural skeleton of his cosmology (Figures 1–2).

Figure 1: The British Library, MS Add. 11416, fol. 147r.

As the diagram suggests, Giqatilla reconfigured the concentric model by integrating the first ten Hebrew letters as ciphers which stand for the ‘parts of the cosmos’. In the manuscripts of Ginnat Egoz, the diagram usually appears as two concentric circles—an inner and an outer sphere. On the inner circumference are inscribed the first ten Hebrew letters, ordered counterclockwise: א, ב, ג, ד, ה, ו, ז, ח, ט, י. These letters, and the Hebrew alphabet more generally, played a significant role in ciphering complex cosmic structures, also due to their numerical value as established in early Rabbinic tradition. The numerology of the Hebrew letters was constructive tool for recasting the relationship between the spheres and parts of the cosmos, as ciphered by the first ten Hebrew letters:

The ten letters correspond to the “ten parts of the universe”, a term which refers to both the number of spheres and to the 10 cosmic qualities that the Hebrew letters carry together with their respective numerical values. The latter is pivotal for the construction of a dynamic cosmos that operates by the qualities epitomized by these linguistic principles. Another pivotal addition is the symbol יא, hovering above the inner concentric letter-arrangement. The numerical value of this symbol is 11, or 10 + 1 (י+א). In Jewish Neoplatonic literature יא often represents the transcendent One in relationship to the tenfold cosmos. In Giqatilla’s diagram it takes on an additional function, namely, the primary principle of divine motion which sustains and governs and spheres.

Figure 2: Paris, Bibliothèque nationale de France, MS Héb, 811, fol. 30r.

The categorical distinction between the ten cosmic parts and the principle of divine motion likely prompted later copyists of the Garden of the Nut to render Giqatilla’s cosmic diagram more schematically. Thus, a sixteenth-century manuscript in (Figure 3) arranges the ten letters on one side of the sphere, directly opposite the symbol יא on the other. Each side bears a heading: ḥelqe ha-galgal (“parts of the sphere”) and tenuʿah יא (‘motion Y‘), respectively. Whereas the diagram in the Paris and London manuscripts can be considered integrative (in the sense that the hovering symbol יא is situated in dialogue with the running alphabetic circle), the diagram in the Munich manuscript is pronounceably schematic.      

Figure 3: Ginnat Egoz, Munich, Bavarian State Library, MS Cod. hebr. 54, fol. 175r.

The idea that the universe consists of the principles embedded in the Hebrew alphabet is central to many Jewish texts, and The Garden of the Nut marks another important moment in this rich speculative tradition. But it also affords us an opportunity to better assess the role that diagrams play in the intersection of cosmology and theology. Particularly, Giqatilla’s letter-cosmography stresses the question whether Kabbalistic diagrams served a goal beyond the mere pedagogical illustration of complex ideas? Addressing this question is also instructive for assessing the manuscript tradition of Giqatilla’s Garden of Nut which includes a markedly distinct rendition of the alphabetic-spherical diagram.  

Abraham Ibn Ezra’s 12th century Arithmetic Cycle

Let us begin by noting that Giqatilla’s diagram has a history. It bears striking allusions to a diagram presented by the Andalusian polymath Abraham Ibn Ezra (12 c.), one of Giqatilla’s major influences. In his Sefer ha-Mispar (“Book of Numbers”), composed over a century prior to The Garden of Nut, Ibn Ezra offered perhaps the earliest systematic Hebrew introduction to the decimal number system. He prefaced it with a brief meditation on the symbolic qualities of the nine numbers and their analogy to the nine spheres encompassing earth:

[The Hebrew word] Sfar refers to the nine numbers, since nine is the end of any reckoning. You should know that the nine are the true numbers which stand against the nine spheres and all the ensuing numbers are assimilated to them

— Abraham Ibn Ezra, Preface to Sefer ha-Mispar, trans. Shlomo Sela (excerpt; adapted).

The first nine Hebrew letters (א–ט) represent the numbers 1–9 and the nine celestial spheres surrounding the sublunary realm. The sequence proceeds counterclockwise, with ṭet (ט, 9) at the apex. Ibn Ezra assumes also the additional symbol 0 (‘void’), functioning as a placeholder within a decimal system. Ibn Ezra is not explicit about the cosmic analogue of the 0, though one might wonder if he had the sublunar realm in mind.

Figure 4: Ibn Ezra, Sefer ha-Mispar; Vienna, Austrian National Library, MS Cod. hebr. D 194, fol. 90v..

While not figured in the diagram, the letter yod (י, 10) is implied as the radix of the decimal system, rather than one of its counted elements. What is significant about Ibn Ezra circular diagram is its arithmetic  mechanism which demonstrates the harmony of the 9 letters and, consequently, of the spheres: Multiplying 9 by any descending integer yields products whose digits are positioned as diametrically opposite pairs.

Figure 5: The Austrian National Library, MS Cod. hebr.  D 194, fol. 90v.

Reconstructing Giqatilla’s Experiment

Ibn Ezra was a polymathic thinker and several of his ideas, in both areas of linguistics and cosmology, became pivotal to Giqatilla. There are grounds to assume that Ibn Ezra’s cosmic diagram was among these adopted ideas, and not simply because of the graphic and doctrinal allusions. If we read Giqatilla’s diagram through Ibn Ezra’s arithmetical logic, its inner workings become clearer. In the discussion following his diagram, Giqatilla introduces various cosmic constructs by manipulating the elements presented in the alphabetic diagram. One of these hermeneutical products is the following fourfold set of letters: “The parts of the sphere [are] אט (AT), בח (BḤ), גז (GZ), דו (DW).”

Figure 6: London, British Library, MS Add. 11417, fol. 147r.

This set alludes to an established Rabbinic hermeneutical formula, known as אטב״ח (ATBḤ), where specific letters in the Hebrew alphabetic system are interchangeable with their respective counterparts – e.g.,  the letter ’aleph (א) with tet (ט), bet (ב) with ḥet (ח), and so forth. Giqatilla adopts this hermeneutical device while recasting its function and significance through the logic of Ibn Ezra’s cosmic-decimal system. He does not spell out his methods, but the logic can be construed if we correctly identify the key variables in his diagram while using Ezra’s system as a frame of reference. The same variables are at play in each of the systems:

  1. The multiplicand – the sequential letters around the circle;
  2. The multiplier – the letter at the apex (ṭet, 9, in Ibn Ezra; yod, 10, in Giqatilla);
  3. The radix – the numerical base that determines the system’s internal coherence.

The crucial change lies in this last variable. The compound symbol יא, whose numerical value is 11 (’aleph + yod), stands above the circle as a new counting base Giqatilla’s diagram therefore operates not on a decimal but on an undecimal system. (Giqatilla uses the symbol יא for this undecimal radix, but for the sake of clarity we may use the letter A as a placeholder for the radix 11, by which logic the number 10 is the last of the counted number: 1-10.)

Figure 7: Paris, BnF, MS héb. 811, fol. 30r.

This small adjustment transforms the arithmetic while recasting the parts of the universe. Where Ibn Ezra’s 9 × 9 produced 81 (אח), Giqatilla’s multiplication (within an undecimal system) yields 73 (גז). Each of the ten letters, multiplied by 10, produces a value recalculated according to base 11. The decimal radix and units’ places are redefined: 10² = 9(A) + 1, where A signifies the new radix 11 and, 1 represents the remainder. Similarly, the product 9 × 10, which equals 90 in decimal terms, becomes 82 in the undecimal system [8(A) + 2]. The letter ח׳ represents the undecimal grouping [8(A)] and 1 constitutes the remainder of the unit digit.

Under this paradigm, Giqatilla reconstructs the ATBḤ letter-pairing formula. From his modified arithmetic emerges the four pairings: אט (AT), בח (BḤ), גז (GZ), דו (DW). Each represents a structural correspondence between cosmic parts as sustained by divine motion, echoing but transforming Ibn Ezra’s earlier decimal pairs (אח, בז, גו, דה). Following Ibn Ezra’s logic, the digits constituting the resulted value stand symmetrically in relationship to the apex (the multiplier), while diametrically opposing each other: אט (AT), בח (BḤ), גז (GZ),  and דו (DW). Similarly, the addition of the two digits/letter of each pair—e.g. א+ט—amounts to the apex (10) and thus completes the order of numbers. Diverging from Ibn Ezra, Giqatilla’s apex is the letter י׳  (rather than ט׳) and, more importantly, the radix, that is, the basis of the system in toto, is the combine letters יא (rather than י׳).

The addition of יא to the cosmic diagram is quite instructive. It reveals how established systems are adopted and further modified by new metaphysical and theological ideas, on the one hand, and with the aid of traditional hermeneutical formulas, on the other. Like other 13th century Kabbalists, Giqatilla developed a distinct cosmology which he based on the active principle of the יא, the latter signifying the One as the direct and active and cause of cosmic motion and its sustainability. No less significant is what Giqatilla’s adopted diagram teaches us about how original theological systems take form. Giqatilla’s model borrows from the available systems of his time while reworking their elements and, at the same time, ‘reinventing’ a new cosmology whose principles and essence assume a different and perhaps more radical conception of creation. Finally, this process of adaptation also shows us why graphic precision is important.  The schematic version of the diagram (Figure 3) loses the entire logic of the spherical letters in relationship to the apex, and their diametric opposition in relationship to each other. I shall conclude this interesting spherical diagram journey, from Ibn Ezra to Giqatilla, with the afterlife of Giqatilla’s Garden of Nut. This work occupies a unique and important place in Kabbalistic literature, and some of its ideas and themes left a noticeable mark on subsequent Kabbalistic developments. One of these themes is the spherical diagram which the fourteenth century Kabbalist Menaḥem Ṣiyyoni incorporated and further reworked in his commentary on the Pentateuch.

Figure 8: Ṣiyyuni, London, British Library, MS Or. 13261, fol. 55r.

Difference and shifts in the process of copying was not unique to The Garden of Nut and here, too, we find interesting variations among manuscripts.

Figure 9:  Ṣiyyuni, Munich, Bavarian State Library, Cod. hebr. 76, fol. 154b.

The diagram is modified considerably in a Munich manuscript. (Figure 9) Not only does it reconfigure the diametric order of the letters, running now clockwise, it repositions the letter yod (י). This letter now initiates a new inner circle consisting of the Hebrew letters י, צ, כ, פ, ל, ע, מ, ס, נ the latter forming the pairs יצ, כפ, לע, מס (These pairs complete the constituents of some version of the Rabbinic ATBḤ hermeneutic formula.)
 
Giqatilla’s ATBḤ sphere provided the basis for further cosmic-theological diagrams. Some of these were modified and integrated into more complex theosophical systems of divine potencies (structured vertically) while borrowing further elements from the hermeneutical ATBḤ formula (Figure 10).

Figure 10: A marginale with the pairs אט בח גז דו יצ כפ לע מס , and with the additional pairs קץ רף שן תם – in a copy of Ḥayyim Vital’s Kabbalistic Derush ATBḤ (16-17 c.). Moscow, Russian State Library, Günzburg Collection, MS 1446, fol. 182r. The last pair תם does not appear in all versions.

All in all, the journey from Ibn Ezra to Giqatilla, and from Giqatilla to later theosophical Kabbalistic texts, offers a glimpse into the workings of a dynamic and creative force of Jewish theological speculation, producing conceptual shifts within a multifaceted intellectual history.

Tzvi Schoenberg, PhD
Arts and Letters Provost Postdoctoral Fellow 
Medieval Institute
University of Notre Dame 

Sources:

The Bavarian State Library, MS Cod. hebr. 54, fol. 175r

The Bavarian State Library, MS Cod. hebr. 76  fol. 154v

The National Library of France, MS héb. 811, 30v

The British Library, MS Add. 11416, fol. 147r

The British Library, MS Or.13261, fol. 55r

The Austrian National Library, MS Cod. hebr. 194, fol. 90v

The Russian State Library, MS Guenzburg 1446, fol. 182r

Further reading: 

Yosef Avivi, Kabbalat ha-Ari, vol. 1 (Jerusalem: Yad Ben-Zvi Institute, 2008), 445 (Hebrew)

Avishai Bar-Asher and Jeremy Phillip Brown, Light is Sown: The Cultivation of Kabbalah in Medieval Castile (New York: Oxford University Press, 2025), 73-115 (esp. 99-106)

J.H. Chajes, “Spheres, Sefirot, and the Imaginal Astronomical Discourse of Classical Kabbalah,” Harvard Theological Review, 113: 2 (2020) 230–262

J. H. Chajes, The Kabbalistic Tree (Pennsylvania State University Press, 2022)

Elke Morlok, Rabbi Joseph Gikatilla’s Hermeneutics (Tübingen: Mohr Siebeck, 2011)

Yakir Paz and Tzahi Weiss, “From Encoding to Decoding: The AṬBḤ of R. Hiyya in Light of a Syriac, Greek, and Coptic Cipher,” Journal of Near Eastern Studies 74: 1 (2015): 95–114

James T. Robinson, “The ‘Secret of the Heavens’ and the ‘Secret of Number’: Immanuel of Rome’s Mathematical Supercommentaries on Abraham Ibn Ezra in His Commentary on Qohelet 5:7 and 7:27”, Aleph, 21:. 2 (2021): 279-308

Shlomo Sela, Abraham Ibn Ezra and the Rise of Medieval Hebrew Science (Leiden: Brill, 2003)

Judith Weiss, “Spherical Sefirot in Early Kabbalah.” Harvard Theological Review 117: 4 (2024): 770-792

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Confinement in Byzantine Narrative, Part I: Martyrs and the Threshold of Holiness

One of the questions that has long fascinated me is how human beings experience the spaces around them, and how those experiences are shaped, narrated, and transformed in literature. In the Byzantine world – stretching from 330, when Constantinople became the new capital of the Roman Empire, to 1453, when it fell to the Ottomans – literature was a window into these experiences, capturing how people imagined and interpreted space.

Among the many spaces that captured Byzantine imagination, few are as revealing as the prison. The narratives of Christian martyrs – stories inspired by the early Christian persecutions (first to fourth centuries) yet mostly composed during the Byzantine era – portray imprisonment not merely as suffering, but as a spiritual turning point. These texts recount the trials of devout men and women who were interrogated, tortured, imprisoned, and executed for refusing to renounce their faith. I first became deeply interested in this topic while examining how confinement was depicted in Byzantine hagiography, a line of inquiry that culminated in my monograph Gefängnis als Schwellenraum in der byzantinischen Hagiographie (Prison as a Liminal Space in Byzantine Hagiography, De Gruyter, 2021) . In this first part of a two-part blog, I return to that subject to explore the prison as a threshold space – one that mediates between human endurance and divine transformation.

Why start with martyrs? Among all genres of Byzantine literature, martyrs’ Passions – accounts of Christian martyrdom – offer the richest and most detailed depictions of imprisonment. These accounts were not only compelling to read but also deeply instructive, showing how imprisonment shaped a martyr’s journey toward holiness. In light of our own recent global experiences of confinement, such as during the COVID-19 pandemic, these medieval depictions of (in)voluntary isolation speak to us in new ways.

Prison as a Threshold

In martyr narratives, the prison is more than a location – it is a liminal space, a threshold between the human and the divine. After enduring brutal tortures, the martyr is thrown into a cell, often bloodied and near death. Conditions are harsh: hunger, thirst, vermin, filth, and extreme overcrowding challenge the body and spirit. Yet, the prison also becomes a space of transformation.

Inside these walls, martyrs pray fervently, and divine intervention is depicted in vivid ways. Christ or angels may appear to heal or strengthen them. Dreams and visions bring the imprisoned closer to God and the promise of Paradise. Simultaneously, martyrs often convert visitors and heal fellow prisoners, demonstrating that the prison is also a space of active spiritual engagement. It is here that martyrs begin to transcend their human limitations and move toward sanctity.

The Martyrdom of Eudoxios, Romylos, Zenon, and Makarios, from an illustrated Menologion (eleventh century, London, British Library, Codex Add. 11870, fol. 67r).  This miniature shows the transition from torture to imprisonment and highlights the prison as a space of spiritual transformation.

Sometimes, the narratives even hint at the possibility of escape, yet martyrs choose to remain. They understand imprisonment as a necessary step on the path to holiness, a phase through which they must pass to achieve ultimate communion with God.

Beyond Martyrs: Voluntary Confinement of Ascetics and Monks

While martyrs faced forced imprisonment, Byzantine literature also explores voluntary forms of confinement, particularly among ascetics and monastics. These individuals deliberately withdrew from society, seeking solitude in caves or cells to cultivate spiritual virtues. Here, too, the space of confinement is transformative.

The ascetic’s cell or cave is not a site of punishment, but of self-imposed discipline. The narratives show how sustained solitude shapes character, deepens devotion, and influences the progression of the story itself. By examining both involuntary and voluntary forms of confinement, we can see a continuum of experiences: whether imposed by external authorities or chosen freely, these spaces are intimately linked with personal and spiritual growth.

The Martyrdom of Lucian of Antioch, from the Menologion of Basil II (ca. 1000, Vatican, Biblioteca Apostolica Vaticana, Codex Vat. gr. 1613, p. 115). The image is divided into two scenes: on the left, Lucian sits alone in his dark cell; on the right, his executioner casts his body into the sea. According to the text, Lucian dies of starvation in prison – his cell thus becomes both his place of death and of spiritual rebirth. The juxtaposition underscores the prison’s central role in shaping the martyr’s fate and ultimate sanctity.

Why These Stories Matter Today

You might wonder: why should readers care about Byzantine martyr narratives today? Part of the answer lies in their timeless human themes. Confinement – whether imposed or voluntary – forces reflection, endurance, and transformation. In our contemporary world, moments of isolation, such as quarantine or personal retreat, echo the ancient experiences depicted in these texts. By understanding how Byzantines imagined and narrated confinement, we gain insight not only into a distant past but also into our own relationship with space, suffering, and growth.

Moreover, these texts offer a rare glimpse into the Byzantine worldview. Hagiographies – texts dedicated to the lives of saints – served multiple purposes: honoring saints, promoting veneration, instructing readers in moral and ethical behavior, and even entertaining them with vivid depictions of daily life, including violence and crime. In this sense, Byzantine hagiographies were a medieval form of “television,” engaging their audience on many levels.

The richness of these texts, preserved across centuries, allows scholars and enthusiasts alike to explore a world where physical spaces and spiritual journeys are inseparably intertwined. The prison is not simply a place of punishment; it is a threshold, a transformative environment, shaping human experience and bringing one closer to the divine.

In studying how Byzantines imagined confinement, we discover not only their mindset, but something essential about ourselves: the ways in which the human spirit turns limitation into transcendence.

Christodoulos Papavarnavas
Visiting Assistant Research Professor
Medieval Institute
University of Notre Dame

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(Pseudo-) Peter Damiani and the Reception of the Schism

In stark contrast to the almost non-reception of the events of 1054 in the literary Byzantine world, discussed here, on the Latin side of the equation, the report of the legation penned by Cardinal Humbert of Silva Candida quickly found its way into various historical chronicles and into theological literature. Two particularly fascinating examples that appear in Patrologia Latina 145 are both published under the name of Peter Damiani, who was, together with Humbert himself, one of the leading members of the papal curia in the mid-eleventh century. Although he would not be elevated to the cardinalate until 1057, under Pope Stephen IX, by the time of Humbert’s legation to Constantinople he was already active in attending various synods and had written the deeply influential Liber Gomorrhianus (addressed to Pope Leo IX). What makes these two works interesting, in light of their purported joint authorship, is that they take views of the azyme conflict (the use of unleavened bread in the celebration of the Eucharist) that are at odds both with each other and with the stance adopted by the Humbertine legation.

Photograph of a bust of Peter Damiani taken from the Florentine church of Santa Maria degli Angeli. Credit to Srnec at English Wikipedia. CC 2.5.

The first example is a letter fragment written by Peter Damiani to Henry, the Archbishop of Ravenna, most likely between 1052 and 1058 [1]. The text is eye-opening both for the historian and for the contemporary canonists, so I’ll cite the full text of Fr. Blum’s translation:

…Just as it makes little difference whether at Mass we offer wine or unfermented grape juice, so, it seems to me, it is all the same whether we offer leavened or unleavened bread. For that “living bread that came down from heaven,” just as he wished to manifest himself under the appearance of wheat, he did so also under the form of the vine. “Unless,” he said, “a grain of wheat falls into the ground and dies, it remains a solitary grain.” And again, “I am the real vine.” Therefore, it suffices for me to offer either whatever is made from grain or whatever is produced by the vine. Nor am I too careful to inquire whether the bread was preserved in an immature dough until it could ferment, or also whether the grape juice was kept in a vat until it could turn into what one calls wine. But since it is not my purpose here to discuss these matters, I leave them to be handled by others…. [2]

Peter Damiani here showed himself to be vastly more permissive than most of the mainstream Latin West when it comes to the correct materials for confecting the Eucharist, and even more tolerant than the legates to Constantinople. Humbert, while he tacitly acknowledged that the Greek practice of using leavened bread was permissible, also had a clear preference for the unleavened Latin host. Peter, interestingly, does not here even mention the Greek practice: his letter is entirely within the context of the Latin rite, addressed to an archbishop of an (admittedly Byzantine-influenced) Latin see. This text allows us to see an approach very different from the one that appears in the aforementioned Liber Gomorrhianus. Given the fact that this was a topic of considerable polemics when he wrote the letter, Peter Damiani appears as a moderating, or even progressive, voice in the conflict.

What a surprise, then, when we examine the second text, taken from the Expositio canonis missae. The work as a whole falls into the genre of Mass commentaries, theological treatises that explain the various ritual components of the eucharistic celebration with historical or scriptural parallels and allegory. Fairly early in this treatise, while discussing the phrase “He took bread” (“accepit panem”) the author complains:

Leavened bread should not be offered in the sacrifice, both by reason of deed and by reason of the mystery. As is read in Exodus: “Leaven signifies corruption”, and as the Apostle witnesses: “A little leaven corrupts the whole lump”. But the Greeks, persisting in their error, celebrate [the Eucharist] from leaven. [3]

Now present is a direct mention of the conflict with the Greeks, using scriptural references that were first applied to the debate by the Humbertine legation. And gone is the tolerance of the previous passage, in which the matter of the Eucharist – so long as it comes from grapes and wheat – is a matter of indifference. Instead, for the author, the use of leavened bread violates the spiritual message of the scriptures, signifying corruption, and is therefore wholly unsuitable for the celebration of the Eucharist. 

The wildly divergent views, of course, lead the reader to question the traditional attributions of authorship for one or both of the passages, and indeed, the Expositio canonis missae has caught the attention of several scholars for containing passages that seem out of place in the literary corpus of Peter Damiani. In particular, the text uses the word “transubstantiation” (“transubstantiatio”), which would be the first appearance of this terminology if it could, in fact, be dated to the middle of the eleventh century. It is this terminological incongruity that caused Joseph de Ghellinck to conduct a line-by-line comparison with other commentaries on the Mass and to conclude that the Expositio postdates not only the De sacramentis of Hugh of St. Victor (d. 1141) but also the De sacro altaris mysterio of Lothar of Segni (later Pope Innocent III), which was written in 1198 [4]. The true date of composition, then, would fall somewhere around the turn of the thirteenth century, about a hundred and fifty years after originally supposed.

When applied specifically to the passage about leavened bread, this reattribution to an anonymous author of the thirteenth century clears up a couple of difficulties. In the first place, the notion of the Greeks persisting “in their error” makes much more sense with the later dating. The use of un/leavened bread in the Eucharist didn’t arise as a point of contention until the 1050s, so the Greeks couldn’t have persisted in the error for very long if it had been Peter Damiani admonishing them. By the year 1200, of course, Latin polemicists could much more reasonably suppose that the Greeks had been given sufficient warning, and therefore that their continued use of leavened bread qualified them as “persisting” (“pertinaces”). Similarly, the hard-and-fast rule that “leavened bread should not be offered” is much more typical of the later period, in contrast with the more permissive attitude found in the eleventh century. We see, for example, an identical notion, in nearly identical phrasing expressed in Lothar’s De sacro altaris mysterio: “Not leavened bread, but rather unleavened, should be offered in the sacrifice, both by reason of deed and by reason of the mystery” [5].

But I want to conclude with an emphasis on the relative openness and permissiveness of the mid-eleventh century. Contrary to the reputation that the events of 1054 have developed in the centuries since, the Latin Christians at that time had only begun to develop their stance on the various points under discussion, un/leavened bread being maybe the most important among them. Had the more irenic figures like Peter Damiani (and even Humbert!) exercised a little more influence on this topic, the West might have maintained a more permissive tone by the time of the authorship of our Pseudo-Peter, and indeed, perhaps a different approach taken under the leadership of Innocent III, who had clearly been swayed by a century and a half of increasing aggressive liturgical polemics in his approach to the Greek rite. Whether openness to a variety of liturgical forms could have prevented the entirety of the calamity of the Fourth Crusade is doubtful, but it certainly couldn’t have hurt.

Nick Kamas
PhD in Medieval Studies
University of Notre Dame

  1. For the Latin text and date, see Kurt Reindel (ed.), Die Briefe des Petrus Damiani, MGG Briefe d. dt. Kaiserzeit 4.2, (München, 1988): 1–2.
  2. Owen Blum (trans.), Peter Damian, Letters 31–60, The Fathers of the Church: Medieval Continuation, (CUA Press, Washington, D.C., 1990): 215.
  3. (Ps.) Peter Damiani, Expositio canonis missae, PL 145.88. “Panis fermentatus non debet offerri in sacrificium, tum ratione facti, tum ratione mysterii. Sic legitur in Exodo. Fermentatum etiam corruptionem significat, teste Apostolo: modicum fermentum totam massam corrumpit. Graeci tamen in suo pertinaces errore de fermento conficiunt.”
  4. Joseph de Ghellinck, Le mouvement théologique du XIIe siècle: études, recherches et documents (Paris: Librairie Victor LeCoffre, 1914), 355–359.
  5. Lothar of Segni (Pope Innocent III), De sacro altaris mysterio, PL 217.854. “Panis autem non fermentatus, sed azymus debet offerri in sacrificium, tum ratione facti, tum etiam ratione mysterii.”