Dante’s open-air treatment of Purgatory seems peculiar to him. Very wonderful is the transition from the dark night of Hell to the “sweet colour of oriental sapphire,” where the star of Love comforts the pilgrim soul, and the four stars of the Southern Cross, which symbolise the cardinal virtues, make all the sky rejoice in their flame--until Easter Day dawns, and from afar the poet “knew the quivering of the sea” (_Purg._ i. 117). Throughout this second Cantica the sun is our guide by day, and at night the stars are over our head; we behold the glory of sunrise and of sunset as upon earth, but with added beauty, for it is attended by celestial songs and the softly beating wings of angelic presences. Dante spends part of four days, with three nights, in this portion of his pilgrimage; for Purgatory is the symbol of the life of man, and the life of man has four periods. At the end of each day Dante rests and sleeps; before dawn on each day, except the first, a vision prepares him for the work of the day--the work which cannot begin or proceed save in the light of the sun, for man can advance no step in this spiritual expiation without the light of God’s grace. But the fourth day does not close, like the other three, in night; for it corresponds to that fourth and last stage of man’s life, in which the soul “returns to God, as to that port whence she set out, when she came to enter upon the sea of this life” (_Conv._ iv. 28). There are three main divisions of the mountain. From the shore to the gate of St. Peter is Ante-Purgatory, still subject to atmospheric changes. Within the gate is Purgatory proper, with its seven terraces bounded above by a ring of purifying flames. Thence the way leads up to the Earthly Paradise; for by these purgatorial pains the fall of Adam is repaired, and the soul of man regains the state of innocence. ANTE-PURGATORY.--In Ante-Purgatory Dante passes Easter Day and the following night. Here the souls of those who died in contumacy of the Church are detained at the foot of the mountain, and may not yet begin the ascent; and the negligent, who deferred their conversion, and who now have to defer their purification, are waiting humbly around the lower slopes. For here purgation has not yet begun; this is the place where time makes amends for time (_Purg._ xxiii. 84).