As they move toward the mountain, Dante notices something strange: he casts a shadow but Virgil does not. This startles him — Virgil gently explains the nature of shades: they can suffer sensation (heat, cold, weight) but cast no shadow and leave no footprint. Dante is moved with pity that Virgil, so great, must exist in this reduced form. Virgil counsels against grief and offers a meditation on the limits of reason: one who would hope to reason through all divine mystery is a fool, for if mankind could grasp everything, there would have been no need for the Incarnation. Even Aristotle tried and failed to fathom the relation between form and matter. This humility before mystery is Virgil's most human quality — and his deepest limitation.
They approach the first slope, steep as a cliff, and encounter a group of souls coming toward them — the excommunicati, those who died under the Church's ban of excommunication. They are not damned; they repented before death. But they must wait in Ante-Purgatory for thirty times as long as they spent in excommunication before they may begin the mountain's climb — unless living prayers shorten their time.
From this group steps Manfred, the natural son of Emperor Frederick II, a strikingly handsome figure even now, his brow split by a sword wound and his chest cloven. He was King of Sicily, excommunicated by the papacy and killed at the Battle of Benevento in 1266 — his body, according to historical report, dishonored by the Church. And yet he is saved. He shows Dante his wounds and recounts that in the very last moment of his life he wept and surrendered himself to God. Even sins as grievous as his were swallowed up by that infinite goodness. The Church may condemn; God is larger than the Church's condemnations. Manfred asks Dante to tell his daughter Constance that he is here, waiting — a plea that humanizes him completely.