Anselm's theological treatise explores the intersection of the Virgin Birth and original sin, presenting a sophisticated understanding of sin as privation of original righteousness rather than a positive corruption transmitted through procreation, while affirming Mary's supreme purity among created beings yet maintaining Christ alone was conceived without sin.

Authorship and Historical Context

Author: The treatise Liber de conceptu virginali et originali peccato (“On the Virginal Conception and Original Sin”) is attributed to Saint Anselm of Canterbury (1033–1109) (Patrologia Latina Database: Bibliography). Anselm, a Benedictine monk and Archbishop of Canterbury, was a leading theologian of the 11th century. He composed this work in 1099 as an extension of his earlier dialogue Cur Deus Homo (“Why God Became Man”) (Anselm of Canterbury - Wikipedia). In the preface, Anselm addresses his close friend and student Boso, indicating that Boso’s inquiries spurred him to write this text to clarify an aspect left open in Cur Deus Homo (Anselm of Canterbury - Wikipedia). The treatise takes the form of a dialogue, essentially a one-sided conversation: Anselm presents his reasoning step by step, anticipating Boso’s questions or objections in a didactic tone (Anselm of Canterbury - Wikipedia) (Anselm of Canterbury - Wikipedia). This method reflects the emerging Scholastic style, using reasoned argument and Q&A format to elucidate doctrine.

Historical setting: Anselm wrote during a time of church reform and intellectual revival. In 1099, he was likely in exile from England (amid the Investiture Controversy) and had recently completed Cur Deus Homo. This milieu gave Anselm the leisure for theological writing and placed him in dialogue with longstanding Christian teachings. By Anselm’s era, core doctrines like the Virgin Birth of Christ and the reality of Original Sin were universally affirmed, but their exact mechanisms and implications (such as how Christ could be born of a human without inheriting sin) invited explanation. Anselm’s approach shows him building on the Church Fathers (especially St. Augustine’s teachings on sin) while also anticipating later Scholastic developments. There is little debate about the authorship – medieval manuscript catalogs (and Migne’s Patrologia Latina vol.158) uniformly list Anselm as the author (Patrologia Latina Database: Bibliography). His secretary and biographer Eadmer of Canterbury preserved and propagated Anselm’s works in the early 12th century, helping secure their transmission.

A mid-12th-century illumination (c.1140) possibly depicting the monk Eadmer of Canterbury writing the life of St. Anselm. Such manuscripts illustrate the immediate context in which Anselm’s works were copied and studied in the generation after his death.

Theological Themes: Virgin Birth, Original Sin, and Mariology

Virgin Birth: Anselm’s treatise centers on the virginal conception of Christ in Mary’s womb and its relation to human sinfulness. He upholds that Jesus was conceived “pure, and free from the sin of fleshly gratification” (The Importance of Saint Anselm of Canterbury for Scotus’ Defense of the Immaculate Conception - Missio Immaculatae Magazine) – a direct affirmation of the Virgin Birth doctrine. The text explores how Christ could take on human nature from a human mother without inheriting original sin. Anselm argues it was “fitting” (Latin: conveniens) for the Redeemer to enter the world through a virgin, in a miraculous conception by the Holy Spirit, in order to break the normal lineage of sin. Yet Anselm pointedly notes that Mary herself was a child of Adam: “the virgin herself, from whom [Jesus] sprang, was conceived in iniquity, and in sin did her mother bear her” (Internet History Sourcebooks: Medieval Sourcebook). This acknowledges that Mary, like all humans, would have been subject to original sin – a crucial issue the treatise addresses. Anselm’s solution emphasizes God’s sanctifying action: it was divinely ordained that Christ’s conception be exempt from any stain of sin, preserving the incarnate Word’s perfect holiness. The Cur Deus Homo dialogue had raised this question, and De conceptu virginali provides the answer: Christ did not contract original sin because God’s grace intervened at the very moment of conception in the Virgin. The virginal conception thus emerges as a necessary, grace-filled exception in the human family, ensuring the new Adam (Christ) was born with a spotless human nature. (Anselm of Canterbury - Wikipedia) (Anselm of Canterbury - Wikipedia)

Original Sin: The treatise offers a nuanced exposition of the doctrine of original sin, building on Augustine but with important development. Anselm defines original sin not as a positive stain transmitted by sexual generation, but as a privation – the absence of original righteousness that Adam and Eve forfeited. He writes that original sin consists in “nothing more than the absence of the state of original justice that man ought to have” (DEPARTMENT OF PHILOSOPHY). Earlier theologians (Augustine included) often correlated the transmission of sin with the act of procreation (the “sinful nature of sex” after the Fall) (Anselm of Canterbury - Wikipedia). Anselm departs from this view. He argues that what Adam bequeathed to his descendants was a nature bereft of justice. In other words, after the Fall, Adam and Eve could not pass on the gift of original holiness which they themselves had lost. Thus, “Adam’s sin was borne by his descendants through the change in human nature which occurred during the Fall. Parents were unable to establish a just [righteous] nature in their children which they had never had themselves.” (Anselm of Canterbury - Wikipedia) Each human, at the moment the rational soul is infused, receives human nature “deprived of original justice” and therefore falls under the condition of original sin (DEPARTMENT OF PHILOSOPHY). Notably, Anselm insists this transmission is “by propagation” of a defective nature, not through any morally illicit act by the parents (Anselm of Canterbury - Wikipedia). This was a significant theological clarification. It preserved the goodness of marriage and sexual union per se (when rightly ordered) – the lack of grace, not lust, is what causes the child to inherit sin. Anselm’s teaching here laid groundwork for later definitions: the Council of Trent would reaffirm that original sin is conveyed by propagation of a fallen human nature, not by imitation or merely personal fault (DEPARTMENT OF PHILOSOPHY).

Mariology: Although the treatise is not primarily a Marian work, it has profound implications for Mariology. Anselm wrestles with Mary’s status as a sinner or sinless. As noted, he explicitly denies that Mary was conceived free of original sin – “she herself sinned in Adam, in whom all men sinned” (Internet History Sourcebooks: Medieval Sourcebook). This places Anselm on the side of tradition that, up to his time, assumed Mary was sanctified but not exempt from original sin from conception. Yet Anselm extols the absolute purity fitting for the Mother of God. In a famous passage, he asserts: “It was proper that this Virgin should shine with a purity than which, apart from God, no greater can be imagined.” (Anselm of Canterbury - Wikipedia) This striking statement (sometimes called Anselm’s “Marian Proslogion” by later commentators) emphasizes Mary’s unsurpassed holiness in creation. Anselm’s logic is one of fittingness (convenientia): if God would create His own mother, it is “proper” that she be as pure as possible, wholly devoted and cleansed for the task (Anselm of Canterbury - Wikipedia). In the treatise, he likely reasons that God did purify Mary at some stage (perhaps at Christ’s conception or beforehand) so that she was personally stainless when bearing the Savior. However, Anselm stops short of claiming Mary was immaculately conceived (a point explicitly denied in his writing). Instead, he holds that Mary, like all descendants of Adam, needed redemption – which, in her case, was applied in a most singular way to make her “that most pure Virgin”. The theological tension here – Mary’s solidarity with all humanity in sin vs. her preeminent sanctity – is a core theme. Anselm’s balanced position safeguarded Christ’s uniqueness (only Jesus was conceived absolutely without any sin) while still according the Blessed Virgin an exalted holiness by God’s grace (Anselm of Canterbury - Wikipedia).

A 12th-century icon of the Annunciation (Novgorod School, Russia) depicts the Archangel Gabriel announcing to the Virgin Mary that she will conceive Christ by the Holy Spirit. This moment – Mary’s virginal conception of Jesus – is the central mystery Anselm examines, explaining how the Virgin Birth could occur without transmitting Adam’s sin.

Patristic and Scholastic Influences

Patristic foundations: Anselm stands on the shoulders of the Church Fathers, especially St. Augustine of Hippo (354–430), in articulating original sin and redemption. He inherits Augustine’s insistence that all humans are implicated in Adam’s fall and require divine grace. Augustine taught that through Adam, “sin came into the world and death through sin” (cf. Rom 5:12), often connecting this transmission with concupiscence in procreation. Anselm largely affirms Augustine’s doctrine of original sin’s universality (he even echoes Augustine in saying all humanity “was in Adam” and fell with him (Internet History Sourcebooks: Medieval Sourcebook)). However, Anselm refines the mechanism of transmission, as described above. In doing so, he actually anticipates later clarifications by Scholastic theologians and the magisterium. We see in Anselm an early exercise of the Scholastic method: he employs rational analysis and precise definition of terms (e.g. distinguishing the state of original justice from the act of begetting) to clarify a mystery that the Fathers handed down. He does not explicitly cite patristic authorities in this dialogue, but Augustine’s influence is evident in the very concern to uphold that “no one (except Christ) is without sin, not even the infant who has lived only one day on earth” (Augustine, De peccatorum meritis). Anselm agrees in principle – hence his refusal to exempt Mary from the fallen condition apart from a special divine intervention (Internet History Sourcebooks: Medieval Sourcebook). We might also detect influence from the Eastern patristic tradition on the Virgin Mary’s holiness. Earlier Eastern writers like St. Ephrem or St. Gregory Nazianzen extolled Mary as “all-pure.” Anselm’s statement of Mary’s unparalleled purity approaches that same sentiment, albeit expressed in his own logical style (Anselm of Canterbury - Wikipedia). Thus, he mediates between patristic reverence for Mary and the doctrinal caution of the Latin West regarding original sin.

Scholastic development: Anselm is often regarded as a forerunner of the Scholastics, and his influence on them was significant (Anselm of Canterbury - Wikipedia). Later 12th–13th century theologians took up the questions Anselm posed. For example, Peter Abelard and Hugh of St. Victor further discussed original sin’s nature, largely in line with Anselm’s privation theory. In the 13th century, St. Thomas Aquinas essentially follows Anselm’s definition: “Original sin is the privation of original justice”, combined with disordering of the soul – a view Aquinas acknowledges had “already been said by others” (Anselm being a chief source) (DEPARTMENT OF PHILOSOPHY) (DEPARTMENT OF PHILOSOPHY). Aquinas, however, differed from Anselm on the Immaculate Conception, maintaining Mary did contract original sin (but was cleansed before birth) – a stance quite close to Anselm’s own position. Meanwhile, the Franciscan school, especially Bl. John Duns Scotus (1265–1308), explicitly drew on Anselm in arguing for Mary’s Immaculate Conception. Scotus cites Anselm’s De conceptu virginali to bolster the logic that Mary’s preservation from sin was possible and fitting. He seized on Anselm’s principles: (1) that God could allow an exception by prevenient grace, and (2) that “apart from God, no greater purity can be imagined” in Mary (Anselm of Canterbury - Wikipedia). Scotus argued that this implied Mary was granted the highest purity (i.e. conceived without sin) – something Anselm himself stopped short of saying. In effect, Scotus solved what Anselm left as a paradox: Anselm saw the fitness of Mary’s immaculate purity but not the fact of it; Scotus proposed that God indeed did it, preserving Mary from original sin in foresight of Christ’s merits (The Importance of Saint Anselm of Canterbury for Scotus’ Defense of the Immaculate Conception - Missio Immaculatae Magazine) (DEPARTMENT OF PHILOSOPHY). Thus, Anselm’s ideas became a springboard for one of medieval theology’s great debates.

Beyond Mary, Anselm’s articulation of how original sin is transmitted influenced scholastic discussions on grace, anthropology, and even the justice of God in condemning unbaptized infants. By locating original sin in the essence of human nature (deprived of grace) rather than in the sexual act, Anselm helped shift the theological focus toward the condition of the soul – a move followed by Aquinas and eventually defined in Church teaching. His method of reasoning through such problems also modeled the scholastic approach of “faith seeking understanding,” harmonizing authority with reason. Later thinkers like Peter Lombard included Anselm’s conclusions in their Sentences, cementing his influence. In summary, Anselm both inherited and enriched the theological tradition: drawing from the Fathers and in turn informing the Scholastics (Anselm of Canterbury - Wikipedia).

Controversies and Reception

Mary’s Immaculate Conception: The most notable theological controversy connected to this work is the question of Mary’s conception without sin. Anselm’s own denial of the Immaculate Conception reflected the common doctrine of his era, yet his emphasis on Mary’s supreme purity planted a seed. In the decades after Anselm, the feast of the Conception of Mary began to spread (first in England). Anselm’s immediate disciples were divided: his nephew Anselm the Younger and his close associate Eadmer actually advocated for Mary’s immaculate conception, inspired in part by the intuition of fittingness that Anselm had articulated (The Importance of Saint Anselm of Canterbury for Scotus’ Defense of the Immaculate Conception - Missio Immaculatae Magazine). Eadmer wrote a treatise De conceptione sanctae Mariae which argued that Mary was preserved from original sin – effectively pushing Anselm’s principles to their logical conclusion. This view, however, met opposition. In 1129, a local council in London approved celebrating Mary’s conception, but on the Continent renowned theologians objected (The Importance of Saint Anselm of Canterbury for Scotus’ Defense of the Immaculate Conception - Missio Immaculatae Magazine). St. Bernard of Clairvaux, in 1140, wrote a letter rebuking the promoters of the new feast, invoking the traditional stance that Mary, like all humans, needed redemption and should not be exempt from Adam’s sin. Bernard’s argument is very much in line with Anselm’s caution: he noted that “the Virgin’s birth should not be celebrated as free of original sin, for that privilege belongs only to Christ”. Throughout the 12th–13th centuries, this remained a theological debate: the Dominican theologians (following Aquinas) mostly held Mary was sanctified after conception, while the Franciscans (following Scotus) held she was immaculate at conception. Anselm’s Liber de conceptu virginali was frequently cited by both sides – his explicit words supported the former view, but his underlying ideas supported the latter. Ultimately, the Immaculate Conception was not defined as dogma until 1854, but medieval reception of Anselm’s work shows him as a pivotal figure: he is sometimes called a “Doctor of Marian Purity” for providing the rationale that later justified the dogma (The Importance of Saint Anselm of Canterbury for Scotus’ Defense of the Immaculate Conception - Missio Immaculatae Magazine) (DEPARTMENT OF PHILOSOPHY), even though he personally did not teach it.

Original sin and human nature: Anselm’s portrayal of original sin as inherited deprivation was widely accepted in the Western Church, and it helped avoid certain controversies. By removing the onus of sin from the physical act of generation, Anselm’s doctrine steered the conversation away from any notion that marital sex was intrinsically evil (a notion some early rigorists flirted with). His explanation was received as orthodox and was later endorsed (in substance) by the Council of Trent. There was, however, some lingering theological curiosity about the precise moment and manner original sin is transmitted – topics later scholastics like Aquinas debated (e.g. does original sin infect the body from the parents and then the soul, or directly at ensoulment?). Anselm had effectively answered that it coincides with the start of personal existence of each descendant of Adam (DEPARTMENT OF PHILOSOPHY). The absence of serious challenge to Anselm’s formulation attests to its soundness. Even Protestant Reformers in the 16th century, while dissenting from Catholic teaching on many points, took no issue with Anselm’s basic notion of original sin as a fallen condition of nature – they in fact radicalized it (teaching total depravity), something Anselm would not have agreed with since he maintained the goodness of nature despite the privation.

Later reputation: Medieval scholars revered Anselm as a Doctor of the Church, and this treatise was copied in collected editions of his works. Its reception by later theologians was generally respectful: De conceptu virginali was mined for arguments about anthropology and Mariology. The two key principles Anselm laid down – the fullness of Mary’s purity and the true nature of original sin – were frequently quoted. By the High Middle Ages, one sees Anselm’s influence in art and literature as well: for instance, in Dante’s Paradiso, St. Bernard (ironically the opponent of the feast) praises Mary using imagery echoing Anselm’s idea that she is the “Termine fisso d’etterno consiglio” (the fixed goal of the eternal counsel) – implying her singular grace. The magisterial definition of the Immaculate Conception in 1854 explicitly cited the tradition that “no purer help than she could be imagined” – a clear nod to Anselm’s formula (Anselm of Canterbury - Wikipedia). Thus, although in his own time Anselm’s cautious position was the norm, in the long run the Church adopted the more “optimistic” view of Mary’s conception, fulfilling the very fittingness Anselm described. His work, then, is a prime example of a theological contribution whose full implications were realized only in later centuries.

Language and Style

Latin style: Anselm wrote in a simple, clear Latin that was typical of monastic scholars of his era. The style of Liber de conceptu virginali is didactic and focused. The Latin is not flamboyant or laden with Ciceronian rhetoric; instead it is concise and logical. Anselm uses short chapters to develop each point stepwise. Surviving manuscripts show the text often came with chapter headings or capitula (the Edinburgh manuscript of the 12th century, for example, lists 18 chapters) (De Conceptu Virginali by Anselm of Canterbury - University of Edinburgh Archive and Manuscript Collections) (De Conceptu Virginali by Anselm of Canterbury - University of Edinburgh Archive and Manuscript Collections). This division reflects Anselm’s methodical approach to complex questions. He often starts by restating Boso’s question or a potential objection, then proceeds to answer it. There is a noticeable repetition of key terms (such as iustitia originalis for original righteousness, peccatum originale for original sin, puritas for purity, etc.) which gives the treatise a disciplined, almost scholastic tone. Anselm’s arguments build on one another in a quasi-syllogistic manner, but he also appeals to fittingness and spiritual intuition, not purely dry logic. For instance, when discussing Mary’s purity, his language becomes almost poetic (“that purity than which a greater cannot be thought” in Latin: puritate, qua maior sub Deo nequit cogitari) – a rhetorical flourish reminiscent of his famous ontological argument phrasing, adapted here for Marian theology (DEPARTMENT OF PHILOSOPHY). Such moments reveal Anselm’s ability to blend rational argument with reverent awe.

Rhetorical features: The treatise maintains a respectful, exhortative tone. Anselm frequently addresses Boso in the second person (e.g. “tuae voluntati, mi carissime Bosone…”, “to your wish, my dearest Boso, … I have done what you asked” in the opening lines (DEPARTMENT OF PHILOSOPHY) (De Conceptu Virginali by Anselm of Canterbury - University of Edinburgh Archive and Manuscript Collections)). This creates a sense of a personal dialogue or a tutorial conversation. It also serves a rhetorical purpose: posing anticipated doubts and then resolving them strengthens the didactic clarity. Anselm employs analogies implicitly – for example, he compares the propagation of sin to the propagation of a defect in a family lineage, to illustrate why an immaculate birth would require special grace. Throughout, Scriptural allusions underpin his points without explicit citation (e.g. he echoes Psalm 51:5 “in sin did my mother conceive me” when affirming Mary’s inherited sin, and Romans 5 when discussing Adam). The style is thus Scripturally infused yet not heavily footnoted – typical of medieval monastic writing where the Bible was so ingrained that direct quotes were often unnecessary.

In terms of structure, De conceptu virginali reads as a companion piece to Cur Deus Homo. Just as Cur Deus Homo was written as a dialogue with Boso about the necessity of the Incarnation and Atonement, this treatise continues the conversation, zeroing in on the Incarnation’s mode (the Virgin Birth) and its sinless nature. The coherence between the two works is evident in the language (Anselm refers back to points made “in that other work”), and it gives the treatise a contextual foundation that readers versed in Cur Deus Homo would appreciate. The Latin used is accessible enough that later medieval readers, and even modern scholars with basic Latin, find Anselm’s prose relatively straightforward to parse, especially compared to the more convoluted style of some 13th-century Scholastics.

Finally, the manuscript tradition shows that scribes sometimes embellished the text with decorated initials. For example, the opening “Cum in omnibus” might be adorned with a painted “C”, though generally Anselm’s text is presented plainly, indicating its use as a scholarly or didactic text rather than a liturgical or devotional piece. The lack of lavish illustration within the treatise (in contrast to, say, a Bible) underscores its purpose as a work of theology and instruction. It was meant to be read, pondered, and discussed, rather than simply admired as literature or art.

In conclusion, Liber de conceptu virginali et originali peccato exemplifies St. Anselm’s genius in theology: it is intellectually rigorous, rooted in tradition, and pastorally oriented (aimed at deepening understanding of Christ and Mary). Its legacy in doctrinal development – especially regarding original sin and Mary’s holiness – testifies to its scholarly depth. At the same time, its clear style and logical argumentation made it a durable contribution, influencing generations of thinkers after Anselm. This treatise stands as a bridge between patristic foundations and scholastic conclusions, and it remains a valuable resource for understanding how the medieval Church grappled with the beautiful mysteries of the Virgin Birth and the tragedy of Original Sin (Anselm of Canterbury - Wikipedia) (Anselm of Canterbury - Wikipedia).

Sources: The analysis above draws on Anselm’s text as found in Patrologia Latina vol.158 and on modern scholarly commentary. Key lines from Anselm’s works and later evaluations have been cited to substantiate points. For instance, Anselm’s own words on Mary’s purity and original sin are referenced (Anselm of Canterbury - Wikipedia) (Internet History Sourcebooks: Medieval Sourcebook), as are interpretations by subsequent theologians and historians (e.g. Janaro’s commentary on Anselm’s Marian principles (DEPARTMENT OF PHILOSOPHY) (DEPARTMENT OF PHILOSOPHY), and Wikipedia’s synthesis of Anselm’s contributions (Anselm of Canterbury - Wikipedia) (Anselm of Canterbury - Wikipedia)). These sources collectively attest to the treatise’s authorship, themes, influences, and lasting impact in Christian thought.