I may have (I think?) mentioned my love for Zacharias Ursinus and his commentary on the Heidelberg Catechism on my old blog. If not, I should mention: Zacharias Ursinus, the primary hand behind the Heidelberg Catechism, wrote a commentary on it that is absolutely fantastic. I still haven't finished it, but it's been thoroughly helpful and stimulating all along.
That said, one can hardly be expected to be fully satisfied by any theological work. In this case, I have found myself struck by what seems to be a pretty significant tension in Ursinus's account of hell and divine justice. With the bulk of the Christian tradition, Ursinus affirmed a doctrine of eternal conscious torment. But his account seems to invite a pretty glaring question. See if you spot it:
God’s justice must be satisfied, even if the whole world should perish. It, moreover, was necessary for him to avenge in this manner the obstinacy of man, from regard to his extreme justice and truth. An offence committed against the highest good, deserves the most extreme punishment, which consists in the eternal destruction of the creature; pg. 101, in Lord's Day 3
The reason which makes this form of punishment [eternal torments] necessary is evident from this: that sin which is committed against God, who is infinitely good, demands an infinite punishment and satisfaction, which could not be rendered by the afflictions which are incident merely to this life. This would not satisfy the infinite and eternal justice of God. pg. 151, in Lord's Day 4
But we cannot make satisfaction by a punishment that is eternal, because then we should never be freed from it. We would always be making satisfaction to the justice of God, and yet it would never be fully satisfied. Our satisfaction would never be perfect—it would never be a complete victory over sin and death, but would continue imperfect to all eternity, as the satisfaction of devils and wicked spirits. pg. 173, in Lord's Day 5
If it be objected, that the devils and the wicked do sustain and are compelled to sustain the eternal wrath of God, we answer, that they do, indeed, sustain the wrath of God, but not so as ever to satisfy his justice, and come out of their punishment. pg. 183, in Lord's Day 6
Sin is an evil of such magnitude, that, according to the order of justice, it merits, and demands, the destruction of the sinner; for the reason, that that which is an offence against the highest good, can only be expiated by the most severe punishment and extreme destruction of the sinner. pg. 408, in Lord's Day 16
If the issue doesn't seem to stand out on its own, here's what I see. On the one hand, Ursinus insists that God's justice must be satisfied, even at the cost of all creation. And this seems quite reasonable. How could the justice of the blessed, almighty, impassible, and utterly sovereign Lord go unsatisfied without the dissolution of all things? It would be like the White Witch said to Aslan about failing to satisfy the magic of the Emperor-Beyond-the-Sea, "all Narnia will be overturned and perish in fire and water." And this very necessity is what Ursinus uses to explain the logic and necessity of eternal torment in hell.
Yet, alongside this, Ursinus also indicates that the infinite gravity of sin's guilt is beyond satisfaction. Sometimes he uses the language of destruction to describe what sin deserves, but elsewhere he explains it with more detail as something that unending suffering will still never be able to fully satisfy. Thus he says that the wicked sustain God's wrath "not so as ever to satisfy his justice."
Thus the tension. "God’s justice must be satisfied" seems rather incompatible with the satisfaction of hell being "imperfect to all eternity." The doctrine espoused seems to leave God's justice perpetually out of balance, God Himself "in the red" eternally. So how could this be resolved?
The proponent of annihilationism or conditional immortality would seem to have an easy solution. Picking up on the occasional reference to "destruction," we could say that the just penalty is not perpetual torment but simply death itself. The infinite debt against God's justice that sin creates is satisfied by the infinite qualitative punishment of a soul being completely abolished. It ends with death, and God's justice is fully satisfied between Christ and the conclusive and entire removal of all the wicked from existence at the last judgment.
Now, as tidy as this solution seems, it does bring us into all of the criticisms ordinarily directed at annihilationism in general. These would need to be addressed, though one might reasonably ask whether these difficulties themselves are not all together still less than the difficulty the doctrine immediately solves.
It remains worth asking, though, if there is a way to resolve this tension without jettisoning the classical doctrine of hell. At least one potential solution does recommend itself. Perhaps the infinite suffering, taken from eternity as a whole, can be regarded as a completed unit. Perhaps immediately in its enactment, as soon as the sinner enters his final fate, justice can be seen as served, since the execution of the full sentence is guaranteed. Whether this is a satisfactory solution or not, I am not prepared to say. Maybe there is yet another possibility. Perhaps I might run across something in Ursinus himself at some point. We're dealing with the edges of human knowledge and the thorniest questions in theology, after all. I certainly don't claim any special insight, but offer everything tentatively, without warranty.