Purgatorio. Purgatorio is the second part of Dante's Divine Comedy, following the Inferno, and preceding the Paradiso. The poem was written in the early 14th century. It is an allegory telling of the climb of Dante up the Mount of Purgatory, guided by the Roman poet Virgil, except for the last four cantos at which point Beatrice takes over as Dante's guide. Purgatory in the poem is depicted as a mountain in the Southern Hemisphere, consisting of a bottom section, seven levels of suffering and spiritual growth, and finally the Earthly Paradise at the top. Allegorically, the Purgatorio represents the penitent Christian life. In describing the climb Dante discusses the nature of sin, examples of vice and virtue, as well as moral issues in politics and in the Church. The poem outlines a theory that all sins arise from love-either perverted love directed towards others' harm, or deficient love, or the disordered or excessive love of good things. As described in the Inferno, the first twenty-four hours of Dante's journey took place on earth and started on the evening of Maundy Thursday, 24 March 1300, and the next full day was spent exploring the depths of Hell with Virgil as a guide. Dante and Virgil spent the next day ascending from Hell to see the stars. They arrive at the shore of the Mountain of Purgatory-the only land in the Southern Hemisphere-at 6 AM on the morning of Easter Sunday, which is 6 PM on Sunday evening in Jerusalem, since the two points are antipodal. Dante describes Hell as existing underneath Jerusalem, having been created by the impact of Lucifer's fall; the Mountain of Purgatory was created by a displacement of rock caused by the same event. The Purgatorio picks up where the Inferno left off, describing Dante's three-and-one-quarter-day trip up the mountain that ends with Dante in the Earthly Paradise at the time of noon on Wednesday, March 30. In Purg. I.4-9, with the sun rising on Easter Sunday, Dante announces his intention to describe Purgatory by invoking the mythical Muses, as he did in Canto II of the Inferno: Now I shall sing the second kingdom there where the soul of man is cleansed, made worthy to ascend to Heaven. Here from the dead let poetry rise up, O sacred Muses, since I am yours. Here let Calliope arise. At the shores of Purgatory, Dante and Virgil meet Cato, a pagan who has been placed by God as the general guardian of the approach to the mountain. The Purgatorio demonstrates the medieval knowledge of a spherical Earth, with Dante referencing the different stars visible in the Southern Hemisphere, the altered position of the sun, and the various timezones of the Earth. For instance, at the start of Canto II, the reader learns that it is dawn in Purgatory; Dante conveys this concept by explaining that it is sunset at Jerusalem, midnight over India on the River Ganges, and noon over Spain. The journey is conceived as taking place during the vernal equinox, when the days and nights are of the same length. By now the sun was crossing the horizon of the meridian whose highest point covers Jerusalem; and from the Ganges, night, circling opposite the sun, was moving together with the Scales that, when the length of dark defeats the day, desert night's hands; so that, above the shore that I had reached, the fair Aurora's white and scarlet cheeks were, as Aurora aged, becoming orange. In a contrast to Charon's ferry across the Acheron in the Inferno, Christian souls are escorted by an Angel Boatman from their gathering place somewhere near Ostia, the seaport of Rome at the mouth of the Tiber, through the Pillars of Hercules across the seas to the Mountain of Purgatory. The souls arrive singing In exitu Israel de Aegypto. In his Letter to Cangrande, Dante explains that this reference to Israel leaving Egypt refers both to the redemption of Christ and to the conversion of the soul from the sorrow and misery of sin to the state of grace. The poets begin to climb in the early hours of morning. On the lower slopes, Dante and Virgil encounter two main categories of souls whose penitent Christian life was delayed or deficient: the excommunicate and the late repentant. The former are detained at the base of the cliff for a period thirty times as long as their period of contumacy. The excommunicate include Manfred of Sicily. Manfred explains that prayer from those currently alive and in the grace of God may reduce the amount of time a soul spends in purgatory. The meeting with Manfred is over by about 9 AM.