The Work
Cur Deus Homo (Why Did God Become Man?) was composed by Anselm of Canterbury in two books, completed around 1098. Written partly in exile - Anselm was in conflict with King William Rufus over church-state questions - the work takes the form of a dialogue between Anselm and his student Boso, who raises objections and receives answers. The treatise is approximately 80 pages in modern translation. Major English translations include those by Edward Gurney (1865), Sidney Norton Deane (1903), and Janet Fairweather in the Cambridge collection Anselm of Canterbury: The Major Works (1998). The Fairweather translation is the most readable.
Biblical Engagement
The treatise builds its argument from Scripture at every stage, though Anselm's method is rational rather than expository - he undertakes to demonstrate the necessity of the Incarnation and Atonement through reason alone, yet the argument continuously engages the biblical framework.
Romans 3:25-26 ("God set forth [Christ Jesus] as a propitiation through faith in his blood, to declare his righteousness for the remission of sins that are past") provides the Pauline frame for Anselm's satisfaction theory. Paul's language of "propitiation" (hilasterion in Greek) and "righteousness" (dikaiosyne) gives Anselm his central problem: how can God be both just and the justifier of sinners? Anselm's answer is that the God-man pays the debt of honor that humanity owes God, satisfying divine justice while extending divine mercy.
Hebrews 9:22 ("without shedding of blood there is no remission") is the axiomatic principle on which Anselm builds his argument for the necessity of the Incarnation. He argues that sin against an infinite God creates an infinite debt; only a being of infinite worth can pay an infinite debt; only the divine Son can be such a being; but only a human being can owe the debt on behalf of humanity; therefore the redeemer must be both human and divine. This argument, which Anselm presents as demonstrating the logical necessity of the Incarnation, draws on the sacrificial logic of Hebrews 9-10.
1 Corinthians 5:7 ("For even Christ our passover is sacrificed for us") locates the atonement within the Passover typology of Exodus 12, which Anselm treats as a prefiguration of the satisfaction Christ offers. The logic of substitutionary sacrifice - one life given in place of many, blood applied to protect from judgment - provides the institutional background for Anselm's conceptual argument.
Isaiah 53:5 ("he was wounded for our transgressions, he was bruised for our iniquities: the chastisement of our peace was upon him; and with his stripes we are healed") is the prophetic warrant for a penal-substitutionary reading of the atonement. Anselm does not use the specific language of penal substitution (that is more Luther's formulation), but Isaiah 53 provides the scriptural model of the suffering servant bearing others' punishment.
Author and Context
Anselm of Canterbury (1033-1109) was born in Aosta, in what is now northwestern Italy, to a noble Lombard family. He entered the Benedictine monastery of Bec in Normandy at age twenty-seven, studying under the renowned theologian Lanfranc. He became prior of Bec in 1063 and abbot in 1078. In 1093 he was appointed Archbishop of Canterbury by King William Rufus - an appointment he accepted reluctantly and which led to years of conflict with both William and his successor Henry I over the respective rights of church and crown.
Anselm wrote Cur Deus Homo during a period of exile (1097-1098), drawing on earlier discussions with the monks at Bec. The treatise was his mature statement of the atonement theology he had been developing through decades of teaching and prayer. The dialogue form - Anselm answering Boso's objections - reflects his actual pedagogical practice: he taught theology through question and answer, pushing his students to understand why Christian doctrines are necessary rather than merely accept them on authority.
Anselm's method - "faith seeking understanding" (fides quaerens intellectum, his definition of theology from the Proslogion) - shapes the treatise throughout. He does not begin from unbelief; he begins from faith and then asks why what faith affirms must be true. This approach, deeply influenced by Augustine, made him the founding figure of medieval scholasticism and the bridge between patristic theology and the universities of the twelfth century.
Critical Reception
The treatise was immediately influential. It gave Western theology its dominant theory of atonement for the next nine centuries. Thomas Aquinas adopted the satisfaction theory, refining it within his synthesis of Aristotelian philosophy and Christian doctrine. The Protestant Reformers - Luther and Calvin - took it in a more explicitly penal direction: where Anselm speaks of satisfaction of divine honor, Luther and Calvin speak of bearing divine punishment. This shift from satisfaction to penal substitution is the major trajectory within the Western atonement tradition Anselm initiated.
Critical responses in the modern period include those of the Swedish theologian Gustaf Aulen, whose Christus Victor (1931) argued that the satisfaction theory was a medieval distortion and that the older "classic" theory of atonement as cosmic battle against Satan and death (drawn from Colossians 2:15 and 1 Corinthians 15:55-57) was more faithful to Scripture. More recently, feminist and womanist theologians including Joanne Carlson Brown and Rebecca Parker have critiqued the satisfaction theory as endorsing patterns of divine violence against the innocent.
Theological Significance
The satisfaction theory introduced by Cur Deus Homo has been extraordinarily generative - not because Anselm settled the question of atonement but because he framed it with such clarity. The concepts of infinite debt, satisfaction, and substitution have shaped not only theology but Western law, ethics, and culture. The very grammar of guilt, debt, and forgiveness in Western moral philosophy is shaped partly by Anselm's categories.
The dialogue form of the treatise was itself significant: it modeled a style of theological inquiry in which objections are taken seriously and arguments must earn their conclusions through reasoning, not just assert them from authority. This approach helped establish the disputation method that became central to the medieval university.
Legacy
The treatise is the most influential work on the doctrine of atonement in Western theology. It was translated, commented upon, and debated through the Middle Ages, the Reformation, and the modern period. Its influence extends beyond theology into law and literature: the language of satisfaction, debt, and redemption that pervades Western culture is partly mediated through Anselm's framework.
Reading Alongside Scripture
Readers should study Romans 3:21-26 (Paul's account of justification and propitiation), Hebrews 9-10 (the high-priestly mediation of Christ and the logic of sacrifice), Isaiah 53 (the Suffering Servant), 1 Corinthians 5:7 (Christ as Passover lamb), and Leviticus 16 (the Day of Atonement ritual) alongside Cur Deus Homo.
Further Reading
- R.W. Southern, Saint Anselm: A Portrait in a Landscape (1990) -- the definitive modern biography, beautifully written. - G.R. Evans, Anselm (1989) -- a concise introduction to Anselm's theology as a whole. - Colin Gunton, The Actuality of Atonement (1988) -- a major constructive engagement with the atonement tradition, drawing extensively on Anselm.