How, although the acts of Christ’s condescension which we speak of do not belong to his divinity, it yet seems improper to infidels that these things should be said of him even as a man; and why it appears to them that this man did not suffer death of his own will.
Anselm. The will of God ought to be a sufficient reason for us, when he does anything, though we cannot see why he does it. For the will of God is never irrational.
Boso. That is very true, if it be granted that God does wish the thing in question; but many will never allow that God does wish anything if it be inconsistent with reason.
Anselm. What do you find inconsistent with reason, in our confessing that God desired those things which make up our belief with regard to his incarnation?
Boso. This in brief: that the Most High should stoop to things so lowly, that the Almighty should do a thing with such toil.
Anselm. They who speak thus do not understand our belief. For we affirm that the Divine nature is beyond doubt impassible, and that God cannot at all be brought down from his exaltation, nor toil in anything which he wishes to effect. But we say that the Lord Jesus Christ is very God and very man, one person in two natures, and two natures in one person. When, therefore, we speak of God as enduring any humiliation or infirmity, we do not refer to the majesty of that nature, which cannot suffer; but to the feebleness of the human constitution which he assumed. 191And so there remains no ground of objection against our faith. For in this way we intend no debasement of the Divine nature, but we teach that one person is both Divine and human. In the incarnation of God there is no lowering of the Deity; but the nature of man we believe to be exalted.
Boso. Be it so; let nothing be referred to the Divine nature, which is spoken of Christ after the manner of human weakness; but how will it ever be made out a just or reasonable thing that God should treat or suffer to be treated in such a manner, that man whom the Father called his beloved Son in whom he was well pleased, and whom the Son made himself? For what justice is there in his suffering death for the sinner, who was the most just of all men? What man, if he condemned the innocent to free the guilty, would not himself be judged worthy of condemnation? And so the matter seems to return to the same incongruity which is mentioned above. For if he could not save sinners in any other way than by condemning the just, where is his omnipotence? If, however, he could, but did not wish to, how shall we sustain his wisdom and justice?
Anselm. God the Father did not treat that man as you seem to suppose, nor put to death the innocent for the guilty. For the Father did not compel him to suffer death, or even allow him to be slain, against his will, but of his own accord he endured death for the salvation of men.
Boso. Though it were not against his will, since he agreed to the will of the Father; yet the Father seems to have bound him, as it were, by his injunction. For it is said that Christ “humbled himself, being made obedient to the Father even unto death, 192 and that the death of the cross. For which cause God also hath highly exalted him;” and that “he learned obedience from the things which he suffered;” and that God spared not his own Son, but gave him up for us all.” And likewise the Son says: “I came not to do my own will, but the will of him that sent me.” And when about to suffer, he says; “As the Father hath given me commandment, so I do.” Again: “The cup which the Father hath given me, shall I not drink it?” And, at another time: “Father, if it be possible, let this cup pass from me; nevertheless, not as I will, but as thou wilt.” And again: “Father, if this cup may not pass from me except I drink it, thy will be done.” In all these passages it would rather appear that Christ endured death by the constraint of obedience, than by the inclination of his own free will.
Source: Cur Deus Homo (CCEL)