Anselm: Christus Victor?
David Bentley Hart argues for continuity between the Patristic understanding of Christ’s atonement and that of Anselm.
Indeed, in Cur Deus Homo the matter of guilt is somewhat recursed: it is guilt that is set aside, made of no account by Christ’s grace, so that the power of death should be overcome without violence to divine justice. From very early on in the text (1.6-7) Anselm is engaged in answering a single question: If the rights of the devil (who is himself infinitely indebted to God) over humanity are not really ‘rights’ in any true sense (a position of the purest patristic pedigree), why must the overthrow of death proceed in the fashion that it does? For God could have reclaimed his creatures by force, if all that were at issue were the devil’s prerogatives (1.7), but for Anselm the true issue is God’s own righteousness. From which unfolds Anselm’s story of the ‘necessity’ – the inner coherence – of the action of the God-man.
Anselm realized that the Devil was not owed anything for the price of man’s redemption. In light of this understanding the situation proves to be much more complicated. God cannot simply overthrow the Devil by force and that be the end of it. If God does not punish man then his own righteousness comes into question. However God loves his creatures and wants to have mercy on them. The only way God can have mercy on man who is guilty is if man pays the penalty for his guilt. This is the job of God’s own Son. Only the Son of God could take on the guilt of mankind and abolish it since all man could do was give God what was already due him. God required a perfect sacrifice who could offer what he did not already owe.
“But Christ of his own accord gave to his Father what he was never going to lose as a matter of necessity, and he paid, on behalf of sinners, a debt which he did not owe.” 
It is Christ who has abolished guilt and displayed the righteousness of God. Anselm believed this work of Christ in upholding the righteousness of God to be his victory over the Devil. Concerning this Hart affirms,
“This is, surely, a variant of a Christus victor soteriology …” 
Of course this does not mean that Anselm was even functioning with a particular Atonement “model.” That is a modern invention.
 Hart, The Beauty of the Infinite: The Aesthetics of Christian Truth, p. 366.
 Anselm, Cur Deus Homo, 2.18.