One of the most striking theological innovations (perhaps more so even than the “Neutrals”) in Dante’s Commedia is his inclusion in Limbo of, not just “little children,” but also of formerly pagan “men and women.” The classic doctrine of Limbo — as articulated by Thomists, for instance (cf. the Supplement to the ST 69.5) — restricts its population to the pre-Christian Hebrew saints (Moses, David, etc.) and unbaptized infants. Dante has both of these classes, but adds to them certain pagans, both from before and after Christ’s advent (whose prime instance in the Commedia is Virgil himself, cf. Inf. 4.39), who “did not sin (non peccaro). Though they have merit, that is not enough, for they were unbaptized…And if they lived before the Christians lived, they did not worship God aright…For such defects, and for no other fault (per tai difetti, non per altro rio), we are lost,” denied the Beatific Vision; though permitted to possess many natural goods, Virgil remarks, “without hope we live in longing” (Inf. 4.34-39, 40-42).
The word that I find most confusing in this passage is “altro“: Virgil might mean that the virtuous pagans are condemned for those defects, and not for any fault (which would square with “non peccaro“). But saying that someone is punished “for no other fault” ordinarily implies that she is punished for some fault. And this reading is commended still further by the fact that Dante even locates some pagans in paradise (i.e., Emperor Trajan, Ripheus of Troy, cf. Para. 20.68, 106-8).
I wonder if Dante is straining in Inferno 4 to quarantine the theological consequences of his novel introduction of pagan men and women into Limbo. The idea that any of them could have lived without sin simply isn’t Christian (i.e., Rom 3:23), and Dante, feeling the weight of this, implicitly acknowledges “faults” in them, though these come short of outright sin.
Theologically, I don’t think there’s much to be salvaged from this scheme — if pagans can come under the operation of the LORD’s grace, then they might possibly be saved; if they die outside the operation of that grace, they will be damned. Attempting to find a place to put sinless pagans is giving a forced answer to a false question.