Pax tecum! Anselm here. I thought it would be fitting to post an excerpt in honor of Holy Saturday from my work on Christ's act of Satisfaction-Atonement, chapter 8: St. Thomas Aquinas on Christ's Descent into Hell.
Master's Thesis: Poena Satisfactoria: Locating Thomas Aquinas's Doctrine of Vicarious Satisfaction in between Anselmian Satisfaction and Penal Substitution (Trumau, Austria: ITI, 2010).
In his commentary on the Apostles's Creed, Thomas gives four reasons as to "why Christ descended with his soul into hell," the first of which is this:
First, in order to endure the entire punishment of sin, in order thus to expiate the entire fault. But the punishment of man's sin was not only the death of the body, but there was also a punishment in the soul: since the sin also had reference to the soul, the soul itself was also punished by the lack of the divine vision: for the removal of which, satisfaction had not yet been made. And therefore, before the coming of Christ, all men descended to hell after death, even the holy fathers. Christ, therefore, in order to endure the entire punishment due to sinners, willed not only to die, but also to descend according to his soul into hell. Whence Psalm 87:4, "I have been counted with those who have descended into the pit: I have been made as a man without help, free among the dead." For the others were there as slaves, but Christ as free. [Aquinas, In Symbolum Apostolorum, 5]
This text immediately appears to imply that Christ descended into hell in order to suffer there the proper punishment of the damned, namely the loss of the vision of God, as if it were somehow necessary for him to endure this in order to make a full satisfaction for sin.
Such a position would imply that the pœna endured by Christ was a pœna simpliciter, according to which the pain itself is regarded as formal in the act of "satisfaction" (understood here simply as punishment) rather than the good offered in compensation out of charity. In this case divine justice appears unwilling to accept anything less than the full punishment due to unredeemed sinners, namely the damnation to which they would have been subject apart from Christ's sacrifice. This also implies an act of substitution in the Lutheran sense of a literal exchange of places between Christ and sinners, rather than the kind of vicarious representation in which Christ steps into the place of sinners without displacing them, but rather incorporating them into himself. In short, such a position implies a penal substitution in the full sense of the words given to them by the Reformation.
The most important thing to notice in this text, however, is Thomas's concluding statement that Christ was among the dead, ut liber (as free). In the Compendium of Theology, Thomas explains this unique freedom of Christ in a text which is crucial for a proper understanding of his interpretation of Christ's descent into hell and therefore also of his doctrine of satisfaction as a whole:
In truth, on the part of the soul it follows among men from sin after death that they descend into hell not only as regards place, but also as regards punishment. But just as the body of Christ was indeed under the earth according to place, but not according to the common defect of dissolution, so also the soul of Christ descended indeed into hell according to place, not however in order to undergo punishment there, but rather to release from punishment those who were detained there on account of the sin of the first parent, for which he had already fully satisfied by suffering death: whence after his death nothing remained to be suffered, but he descended into hell locally without suffering any punishment, that he might show himself as the liberator of the living and the dead. From this also it is said that he alone was free among the dead, because his soul was not subject to punishment in hell, nor his body to corruption in the tomb. [Aquinas, Compendium theologiae I, cap. 235]
This text makes it very clear that for Thomas there can be no question of Christ suffering any kind of punishment in hell.
The parallelism presented here between tomb and hell is also instructive. In his treatise on the humiliation of Christ in the Summa theologiæ (III, qq. 46-52), Thomas considers his passion (qq. 46-49), and then his death as the state of separation of soul and body (q. 50). This is followed by parallel questions on the burial of his body (q. 51) and the descent of his soul into hell (q. 52). That Christ descended into hell in order to endure the entire punishment of sin means for Thomas that he willed to endure physical death fully, from the suffering which precedes death, through the separation of soul from body in which it is consummated, to its completion in the resting places of soul and body apart from each other. The descent of Christ into hell according to his soul bears the same relation to punishment as the burial of his body: "just as Christ, in order to take upon himself our punishments, willed his body to be placed in the tomb, so also he willed his soul to descend into hell." [Aquinas, Summa theologiae III, q. 52, a. 4] The descent itself, like the burial, is penal only inasmuch as it is the completion of death, but Christ's soul does not suffer in hell any more than his body suffers in the tomb.
Contrary to Balthasar, who holds that Christ had to endure both a natural death (the separation of the soul from the body), and the "second death" spoken of in the Revelation to John (Rev. 2:11; 20:6, 14; 21:8), the spiritual death of the soul (that is, the separation of the soul from God), in order to fully free man from this twofold death, Thomas clearly holds that Christ's one (natural) death is itself more than sufficient for this purpose, as can be seen in the mystical interpretation which he gives to the two nights and one whole day that Christ spent in the tomb (and in hell):
[B]y the death of Christ we have been liberated from a double death, namely from the death of the soul and from the death of the body: and this is signified by the two nights through which Christ remained in the tomb. His death, however, not coming forth from sin, but undertaken from charity, had not the account of night, but of day: and therefore it is signified by the whole day in which Christ was in the tomb. [Aquinas, Summa theologiae III, q. 51, a. 4]
Another important text for an accurate understanding of Thomas's doctrine of the descent of Christ's soul into hell can be found in his commentary on the Sentences of Peter Lombard, his first major work. There he reiterates the principles on the basis of which he excludes any pain or suffering from the soul of Christ in hell. The Incarnation was ordered toward salvation, for the accomplishment of which God had chosen to require satisfaction. In assuming a human nature therefore Christ willed to take upon himself certain defects, according to a twofold criterion: they should be those which were common to all men on account of sin, yet did not imply or even incline toward any defect of grace or virtue. That a soul should descend into hell after death was, before Christ's coming, common to all men on account of original sin, and so Christ also endured this, descending locally into hell. Thomas then considers each possible kind of punishment (pœna), and concludes that Christ cannot have suffered any of them in hell. The pain of loss (pœna damni), which is the lack of the vision of God, would clearly imply a defect of the consummate grace of glory, and hence is excluded. The pain of sense (pœna sensus) could be either satisfactory (pœna satisfactoria), purgative (pœna purgativa), or damnative (pœna damnativa). Now pain cannot be satisfactory after death inasmuch as satisfaction, like merit, belongs to the state of the viator, to this earthly life alone; but purgative pains (after death) are only due on account of impurity and damnative pains on account of mortal sin, either of which would imply a defect of grace. Hence: "It was befitting to Christ to descend into hell insofar as it implies a place, but not insofar as it implies punishment." [Aquinas, In III Sententiarum, d. 22, q. 2, a. 1a]
Although a single text taken out of context can easily give the impression that Thomas holds essentially the same doctrine of penal substitution as Calvin, namely that in order to pay the debt due to sin Christ had to suffer the pain proper to damnation (which consists essentially in the loss of the vision of God), Thomas's parallel texts on the same topic make it abundantly manifest that this is not the case. According to Thomas, Christ descended locally into hell in order to endure death all the way through to the end, but his soul did not suffer there. On the contrary, he came to release from their punishment and from the captivity of the conquered devil the souls of the holy fathers who were detained there on account of original sin, which he accomplished with such a manifestation of power that, although he entered only into the limbo of the fathers according to his essence and freed only them, even the damned felt the power of his presence.