The satisfaction theory of atonement is a theory in Catholic theology which holds that Jesus Christ redeemed humanity through making satisfaction for humankind's disobedience through his own supererogatory obedience. The theory draws primarily from the works of Anselm of Canterbury, specifically his Cur Deus Homo ("Why was God a man?"). It has been traditionally taught in the Roman Catholic tradition of Western Christianity. Since one of God's characteristics is justice, affronts to that justice must be atoned for. It is thus connected with the legal concept of balancing out an injustice. Anselm regarded his satisfaction view of the atonement as a distinct improvement over the older ransom theory of atonement, which he saw as inadequate, due to its notion of a debt being owed to the devil. Anselm's theory was a precursor to the innovations of later theologians like John Calvin, who introduced the idea of Christ suffering the Father's just punishment as a vicarious substitute. Early development of the theory The classic Anselmian formulation of the satisfaction view should be distinguished from penal substitution. Both are forms of satisfaction theory in that they speak of how Christ's death was satisfactory, but penal substitution and Anselmian satisfaction offer different understandings of how Christ's death was satisfactory. Anselm speaks of human sin as defrauding God of the honour he is due. Christ's death, the ultimate act of obedience, brings God great honour. As it was beyond the call of duty for Christ, it is more honour than he was obliged to give. Christ's surplus can therefore repay our deficit. Hence Christ's death is substitutionary; he pays the honour to the Father instead of us paying. Penal substitution differs in that it sees Christ's death not as repaying God for lost honour but rather paying the penalty of death that had always been the moral consequence for sin (e.g., ; ). The key difference here is that for Anselm, satisfaction is an alternative to punishment, "it is necessary either that the honor taken away be repaid, or else that punishment follow." By Christ satisfying our debt of honor to God, we avoid punishment. In Calvinist Penal Substitution, it is the punishment which satisfies the demands of justice. Another distinction must be made between penal substitution (Christ punished instead of us) and substitutionary atonement (Christ suffers for us). Both affirm the substitutionary and vicarious nature of the atonement, but penal substitution offers a