Cur Deus homo?
Quick Summary
Cur Deus homo? (Why Did God Become Man?) is a seminal work by St. Anselm of Canterbury written around 1099. In this text, Anselm presents a rational explanation for the Incarnation of Jesus Christ. He argues that human sin created an offense against God's infinite justice, which humanity could not rectify on its own.12
Anselm's theory of atonement posits that only a being who is both fully God and fully human could provide the necessary satisfaction for this offense. God, being sinless, could overcome sin, while being human meant that this divine being could represent and act on behalf of sinful humanity. Therefore, Christ's death on the cross was not a ransom paid to the Devil, but a necessary act of satisfaction to restore the moral order and reconcile humanity with God. This work significantly influenced later Christian theology regarding the purpose of Christ's sacrifice.21
Ask Britannica AI about this topic
Britannica doesn't have a full article on this topic, so we've curated a list of our relevant coverage.
JesusThe medieval developmentAtonement, summarized in his book, Cur Deus homo? According to that doctrine, sin was a violation of the honor of God. God offered human beings life if they rendered satisfaction for that violation, but the longer a person lived, the worse the situation became. Only a life that was truly…
Read MoreAtonement, summarized in his book, Cur Deus homo? According to that doctrine, sin was a violation of the honor of God. God offered human beings life if they rendered satisfaction for that violation, but the longer a person lived, the worse the situation became. Only a life that was truly…
Read More
ChristologyThe Middle AgesIn his epochal work Cur Deus homo (“Why God Became Man”), however, St. Anselm of Canterbury (1033/34–1109) formulated the most-trenchant theory of the Atonement of Christ. Anselm held that Jesus’ death on the cross was absolutely necessary because there was no other rationally intelligible way in which sinful humankind…
Read MoreIn his epochal work Cur Deus homo (“Why God Became Man”), however, St. Anselm of Canterbury (1033/34–1109) formulated the most-trenchant theory of the Atonement of Christ. Anselm held that Jesus’ death on the cross was absolutely necessary because there was no other rationally intelligible way in which sinful humankind…
Read More

