In Purgatorio, the angel draws seven P’s on Dante’s forehead. Each P represents peccatum, the Latin word for “sin,” and the seven letters symbolize the seven deadly sins that Dante must overcome on Mount Purgatory.
The marks are connected to the seven terraces of Purgatory: pride, envy, wrath, sloth, avarice, gluttony, and lust. After Dante passes each terrace, an angel erases one P from his forehead. As the marks disappear, the ascent becomes easier, showing that spiritual purification removes the burdens weighing on his soul.
The first P is erased by the Angel of Humility after Dante leaves the terrace of pride. The gesture also creates a visible moral progress report: Dante does not merely travel upward through a physical landscape; he is being transformed. The letter M is a tempting alternative because the sins are moral categories, but Dante’s repeated mark is specifically P for peccatum.