Canto IX. Dante dreams that he has been caught up by an angel, and wakes to discover that he has in fact been carried up the slopes to the gate of Purgatory by St Lucy. The angel who guards the gate allows him passage when he hears that St Lucy has directed the poets to the entrance. Dante must ascend three steps to the gate, and kneels before the angel who marks three ‘P’s on his forehead, each standing for peccatum, sin, and representing the seven capital sins purged on the terraces of the mountain. Dante then passes through the gate.

This canto is rich in symbolism. Perhaps most pressing in Lent are the three steps. The first is of shining white marble, in which Dante can see his own reflection. The second is dark, coarse grained stone, cracked in the form of a cross. The third is blood-red porphyry. The marble, in which the face is clearly seen, represents confession, the first part of the sacrament of penance in which the penitent truthfully acknowledges his guilt. The second, black and broken, represents contrition, a true sorrow for sin. The third, red, represents satisfaction. As Dorothy Sayers points out, satisfaction is made primarily by the sacrifice of Christ, but also by our joining to his our sacrifice in which we seek, by God’s grace, to amend our lives and so offer ourselves to him. As Herbert McCabe puts it, in penance we detach ourselves, perhaps painfully, from the damaging attachments that sin creates.