CUR DEUS HOMO? by Anselm of Canterbury

Published on November 14, 2017 by Joshua R Monroe

Oxford University Press, 2008 | 544 pages

A Brief Book Summary from Books at a Glance

By Ben Rogers


About the Author

Anselm of Canterbury (1033-1109) was a native of Aosta and the son of the Lombard landowner. He left home for France in 1056 and entered the monastic school at Bec in Normany in 1059, which was directed by the famous teacher Lanfranc of Pavia. He took monastic vows in 1060, succeeded Lanfranc as prior in 1063, and became abbot in 1078. He would go on to follow Lanfranc as the Archbishop of Canterbury in 1093, and publish a number of important theological and philosophical works over the course of his career, including Monologion, Proslogion, and De Processione Sancti Spiritus, as well as his theological masterpiece on the atonement, Cur Deus Homo. He is regarded by many as “The Father of Scholasticism” and the most important Christian philosopher-theologian between Augustine and Aquinas.



Cur Deus Homo was written between 1094 and 1098 in response to two different challenges to the Christian faith: the Jewish criticisms of Christian doctrine and the theological debates of the secular schools. Jewish opponents questioned the necessity, possibility, and dignity of the incarnation and atonement. The schoolmen argued that God became man simply to deliver man from the dominion of the Devil. Against the former Anselm argues that the incarnation and atonement are not only necessary and possible, but “most fitting,” “inexpressibly beautiful,” and in perfect harmony with God’s honor. Against the latter he argues that God became man not to merely trick Satan into overstepping his authority but to make satisfaction for sin.

The work takes the form of a discussion between Anselm and his favorite pupil, Boso, who gives voice to the questions of unbelievers and believers. Their conversations are divided into two books and each book is subdivided into multiple chapters. In Book I Anselm answers the objections of unbelievers who reject the Christian faith because it appears to be contrary to reason (chs. 1-10), and then proves by necessary reason that it is impossible for any man to be saved apart from Christ (chs. 11-25). In Book II he argues that it is only possible for man to achieve the purpose for which he was created – blessed immortality – through a God-man, and thus everything Christians believe about Christ’s incarnation and atonement must necessarily take place.


Outline of the Argument

  • God made man for eternal blessedness.
  • Man fell from his original state, forfeited eternal blessedness, and ruined the entire race through sin.
  • The remission of sins in necessary for fallen man to arrive at eternal blessedness.
  • In order for sins to be remitted, satisfaction must be made.
  • Only man ought to make satisfaction for his sin, but he cannot.
  • Only God can make this satisfaction, but he ought not.
  • Since only man ought to make satisfaction, and only God can, it must be made by a God-man.
  • If man remains unredeemed, God’s purpose for humanity and creation will be frustrated, which is impossible for an omnipotent Being.
  • Therefore, a God-man is necessary for the redemption of humanity.




Book I

Chapter 1: The Question on Which the Whole Work Depends.

Anselm opens by explaining the purpose, central question, and methodology of the work. Cur Deus Homo was occasioned by repeated requests for proof about the incarnation and atonement. Unbelievers reject them as unreasonable and unfitting for God, and the faithful desire to more fully understand the things they already believe. The question that both want answered is this: why did God Almighty become man and die to redeem humanity from sin, when he could have done this in another way or through another person? In other words, what reason or necessity lay behind the incarnation and atonement? In order to answer this question with the utmost clarity, Anselm adopts a debating format in which Boso presents the questions/objections and Anselm answers them.


Chapter 2: How What Is to Be Said Should Be Taken.

After stating the question in chapter 1, Anselm makes a proviso. If, in answering a question, he proves something by reason that is not supported by a greater authority, his answer should not be treated as more certain than is warranted.


Chapter 3: The Objections of Unbelievers and Replies of the Faithful.

The first, and perhaps, chief objection to the incarnation and atonement is that it is unfitting for God to endure such extreme humiliation – i.e. birth, rejection, suffering, and death.

Anslem argues that man’s redemption does no insult or injury to God’s honor. On the contrary, it exalts his ineffable love and mercy. Moreover, it is eminently fitting as well. Since death entered the human race through the disobedience of man, it is fitting that life should be restored through the obedience of man. Since sin and condemnation had their beginning with a woman, it is fitting that the author of righteousness and salvation be born of a woman. And since the devil conquered man by the tasting of a tree, it was fitting for him to be conquered by man’s bearing of suffering on a tree.


Chapter 4: These Answers Seem to Unbelievers to Be Inconclusive, and like So Many Pictures.

Boso admits that these things are, in fact, beautiful, but are they rationally sound? Unless it can be proven that the incarnation and atonement were necessary, fitting, and possible, then unbelievers will never believe the truth of them.

Anselm begins his defense of the rational soundness of his position by making three assertions:

The human race – God’s crowning creation – was altogether ruined
It is not fitting for God’s plan for man – eternal blessedness – to be entirely wiped out
This plan cannot now be put into effect unless humanity is delivered by the Creator himself.


Chapter 5: The Redemption of Man Could Be Accomplished by No One Except God.

Boso questions the third of the previous assertions. Why couldn’t man be delivered by an angel or another man?
This, according to Anselm, is impossible. If man was rescued from judgment by another man (or angel), he would be a servant or debtor to that man (or angel) and not God alone, which would be idolatry. Moreover, such a deliverance would not restore man to his original pre-fall dignity. Man, as created, was a servant of God alone and an equal to holy angels.


Chapter 6: How Unbelievers Criticize Us When We Say that God Has Redeemed Us by His Death, that He Has Thus Shown His Love toward Us, and that He Has Come to Conquer the Devil on Our Behalf.

Boso then asks about the nature of man’s bondage. What is the bondage or captivity that only the death of God can deliver man from? He anticipates the standard Christian response – sin, wrath, hell, and the power of the Satan – but this raises a number of other question about God’s power, wisdom, love, and his relationship to the Devil. If God is all-powerful, then why didn’t he simply redeem man by a simple command? And if he is, how can it be proven that he is all-wise for choosing such a humiliating means of redemption? Furthermore, could God not have demonstrated his love for man in some other way? And finally, why did God have to become a man to defeat the Devil? Doesn’t his omnipotence extend over his enemies?


Chapter 7: The Devil Had No Justice on His Side Against Man. Why He Seems to Have Had It. Why God Delivered Man in This Way.

Boso continues by inquiring into the nature of God’s conflict with Satan. Why was God bound to strive with the Devil by justice, rather than by force? Since both Satan and man are both God’s creatures, why did he have to plead with one over the other? Moreover, though the Devil justly torments man for his sin, he does so unjustly – i.e. he has no love of justice, no contract with God, and is himself absolutely unjust. Therefore, there is no reason, as far as the Devil is concerned, why God should not use his power against him to deliver man from his torment.


Chapter 8: How, Although the Lowly Things We Ascribe to Christ Do Not Belong to His Divinity, Unbelievers Find it Unseemly for Them to Be Attributed Even to His Manhood, and Why They Do Not Think that This Man Died Willingly.

Boso sums up the previous arguments (chs. 6-7) by simply stating that unbelievers find the incarnation and atonement contrary to reason because they entailed so much humiliation and labor upon God.

Anselm begins his response by reminding Boso that Christians do not attribute humiliation and weakness to Christ’s divine nature, but to his human nature, and thus they believe nothing that is contrary to reason or unfitting about God.

Boso accepts Anselm’s answer, but then asks why is it just or reasonable for the Father to condemn his innocent Son in order to free the guilty? If this is the only way to was to rescue man, then calls into question God’s power, wisdom, and justice once again.

Anselm responds by pointing to the voluntary nature of Christ’s death. The Father did not condemn the Son against his will, but he willingly and readily endured death to save men.

Boso counters by pointing to a number of Biblical texts (Phil. 2:8; Heb. 5:8; Rom. 8:32; John 6:38; John 14:31, Matt. 26:39, 42) that seem to suggest that Christ was compelled to die by his Father’s command, which undermines the voluntary nature of the atonement.


Chapter 9: That He Died Voluntarily, and What It Means to Say That “He Became Obedient Unto Death,” and “For Which Cause God Also Hath Exalted Him,” and “I Came Not to do Mine Own Will,” and “God Spared Not His Own Son,” and “Not as I Will, but as Thou Wilt.”

After offering explanations for the aforementioned texts, Anselm concludes that the Father willed the death of his sinless Son, not because the Father preferred the death of his Son to his life, but because he was unwilling for the human race to be restored unless man performed some great act, equal to the Son’s death. And since no one else could achieve this, for the Son, who willed the salvation of men, this amounted to the same thing as if the Father had commanded him to die.


Chapter 10: Another Correct Interpretation of the Same Statements Is Possible.

Anselm offers more interpretations of the previous texts. He argues that since the Father willed the salvation of men, and since the death of his Son was the only way to save the them, therefore the Father willed the death of his Son rather than leaving the world unsaved.

Even so, Boso argues, it is unfitting for such a Father to allow such a Son to endure such treatment even though he did so willingly.

Anselm replies that it is supremely fitting for such a Father to permit such a Son to do what he will for the glory of God and the salvation of men, when no other way was possible.

Boso remains unconvinced. Though Anselm has answered his questions, he still has not shown why the incarnation and atonement are both necessary and reasonable. Not only does it seem unfitting for God to have saved man in this way, it is not clear why that death should avail for man’s salvation.

Anselm’s response to this last question takes up the rest of Book I (chs. 11-25). He intends to show by necessary reason alone that it is impossible for man to be saved apart from the incarnation and atonement, and he concludes the chapter by discussing the “ground rules” of the new discussion. Nothing is to be believed unless it is first proved by reason. Nothing unfitting shall be attributed to God. No reason shall be rejected unless a weightier one is opposed to it. It will be supposed, for the sake of argument, that the incarnation never happened. And it is agreed that: 1) man was made for eternal blessedness, which cannot be attained in this life; 2) while no man can reach it unless his sins are forgiven, no man passes through this life without sin; 3) therefore, the remission of sins is necessary for a man to arrive at eternal blessedness.


Chapter 11: The Meaning of Sin, and of Satisfaction for Sin.

Anselm and Boso begin their new discussion by defining two critical terms: sin and satisfaction. Sin is defined as not rendering God his due or violating his will in any way. Satisfaction, on the other hand, is more than simply repaying God for one’s sins, it is repaying to God’s honor all that has been taken away by sinning. This, according to Anselm, is the satisfaction every sinner ought to make to God.


Chapter 12: Whether It Would Be Fitting for God to Forgive Sins by Mercy Alone, Without Any Payment of Man’s Debt.

Anselm asks whether it would be fitting for God to simply forgive sin by mercy alone without requiring satisfaction for sin. Boso affirms that it would be fitting, but Anselm disagrees. To do so would be both unfitting and unjust. To remit sin without punishment would create irregularity in God’s kingdom. It would place the righteous and the unrighteous in the same position, and it would make the kingdom of God less just than the kingdom of men.

Boso raises the question about Christ’s command to forgive those who sin against us (Matt. 6:12). It is inconsistent for God to command us to do something that is improper for him to do himself.

There is no inconsistency, according to Anselm, because God is forbidding us from exercising a prerogative – taking vengeance – that belongs to him alone. . . .

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Anselm of Canterbury: The Major Works

Oxford University Press, 2008 | 544 pages

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