  So the restoration of human beings to the justice they were intended to enjoy requires divine grace. But even more is needed than God’s restoration of the will for justice. In Cur Deus Homo (Why God Became A Human Being, or Why the God-Man?) Anselm famously attempts to show on purely rational grounds that the debt incurred by human sin could be suitably discharged, and the affront to God’s infinite dignity could be suitably rectified, only if one who was both fully divine and fully human took it upon himself to offer his own life on our behalf.