Prohibition against looking back

The Prohibition against looking back is a stern rule imposed at the very threshold of Purgatory, a condition that transforms the act of entering into a test of the pilgrim's will. When Dante and Virgil arrive at the Gate of Purgatory, the angelic gatekeeper, seated on the threshold of diamond, pushes open the sacred portals and issues a stark warning: "Enter; but I give you warning / That forth returns whoever looks behind." This command is not merely a practical instruction but a spiritual ordinance that defines the nature of the penitential ascent. The gate itself, made of metal and sonorous, roars as it turns on its hinges, a sound that recalls the Tarpeian rock when the good Metellus was taken from it, and the first thing Dante hears after the thunder-peal is the "Te Deum laudamus" mingled with sweet melody. The prohibition thus frames the entrance as a point of no return, where the soul must commit itself wholly to the path ahead, abandoning any lingering attachment to the past or to the world left behind.

The Gatekeeper's Warning and Its Immediate Context

The prohibition is delivered by the angel who guards the Gate of Purgatory, a figure described as having a face so radiant that Dante cannot endure it, and who holds a naked sword that reflects the sunbeams so brightly that the poet can scarcely lift his eyes. The angel sits on the highest of three stairs, each of a different color: the first is white marble, polished and smooth, in which Dante sees himself mirrored; the second is a dark, calcined stone, cracked all asunder; the third is porphyry, as flaming red as blood spurting from a vein. After Dante prostrates himself at the angel's feet and beats his breast three times, the angel inscribes seven P's on his forehead with the sword's point, saying, "Take heed that thou wash / These wounds, when thou shalt be within." Then, drawing forth two keys—one of gold and one of silver—the angel plies the door, explaining that if either key fails to turn rightly, the entrance does not open. It is immediately after this ritual that the angel pushes the portals and pronounces the prohibition against looking back, making clear that the rule is integral to the act of entering the penitential realm.

The Prohibition as a Spiritual Principle

The prohibition against looking back is not an isolated command but a principle that resonates throughout the Purgatorio, reflecting the soul's need to sever itself from the past and to focus entirely on the journey toward God. This rule echoes the biblical story of Lot's wife, who was turned into a pillar of salt for looking back at Sodom, and it aligns with the broader theme of Purgatory as a place where souls must abandon their former sins and attachments. The gatekeeper's warning is the first explicit articulation of this principle at the threshold, but it is reinforced later in the poem. In Canto XIX, after Dante has passed through the gate and is ascending the mountain, Virgil instructs him to "smite earth with thy heels" and lift his eyes upward to the lure that whirls the Eternal King, a command that similarly demands forward orientation. The prohibition thus functions as a spiritual discipline, training the will to resist the temptation to dwell on what has been left behind, whether it be sin, worldly attachments, or the comforts of the past.

The Prohibition's Role in the Structure of Purgatory

The prohibition is part of a larger set of rules that govern the ascent of Mount Purgatory, including the nocturnal prohibition on climbing (which forces pilgrims to stop at nightfall) and the requirement to follow the path without deviation. These rules collectively establish Purgatory as a realm of order and discipline, where the soul must submit to a regimen that prepares it for Paradise. The gatekeeper's warning is the first such rule encountered after the gate, and it sets the tone for the entire journey: the pilgrim must not look back, must not waver, and must trust in the guidance of his leaders. This forward-looking imperative is later echoed in the words of Virgil, who tells Dante that he has brought him to the Earthly Paradise and that henceforth Dante must take his own pleasure for his guide, for he is "free and upright and sound" in his free will. The prohibition against looking back thus marks the transition from the passive suffering of Hell to the active, hopeful striving of Purgatory, where the soul must consciously choose to move forward.

The Prohibition and the Theme of Memory and Forgetting

The prohibition also engages with the theme of memory and forgetting that pervades the Purgatorio. The souls in Purgatory are engaged in a process of purgation that involves both remembering their sins (so as to repent) and eventually forgetting them (through the waters of Lethe). The command not to look back can be seen as a way of preventing the soul from becoming trapped in a nostalgic or regretful fixation on the past, which would impede its progress. Later, in the Earthly Paradise, Dante will drink from Lethe, which erases the memory of sin, and from Eunoe, which restores the memory of good deeds. The prohibition at the gate thus anticipates this later purification, insisting that the soul must not cling to the past even as it undergoes the painful process of recalling and repenting its sins. The rule is a practical expression of the theological virtue of hope, which looks forward to future glory rather than backward to past failures.

The Prohibition's Significance for Dante's Journey

For Dante personally, the prohibition against looking back is a crucial test of his resolve. Having just emerged from the horrors of Hell, he might be tempted to look back at the infernal realm or to doubt the wisdom of his journey. The gatekeeper's warning, delivered with the authority of the keys of St. Peter, makes clear that any such backward glance would result in immediate expulsion, undoing all the progress he has made. This threat reinforces the gravity of the moment and the irrevocability of the choice to enter Purgatory. It also aligns with the broader theme of Dante's journey as a movement from error to truth, from the dark forest to the vision of God. The prohibition is a reminder that the path to salvation requires a complete break with the past and a total commitment to the future, a commitment that Dante must renew at every stage of his ascent. The rule thus serves as both a practical instruction and a profound spiritual symbol, encapsulating the essence of the penitential life.