The waters of Purgatory are called "the waters of peace which are the souls diffused from the eternal fountain" (XVI, 133). Dante addresses the souls as certain of gaining the unending peace of Paradise. "O Souls, sure in the possession whenever it may be of a state of peace" (XXVI, 54). And when the day of release comes on which a soul attains perfect peace, the whole mountain of Purgatory literally thrills with joy and every voice is raised to join the harmonious concert of the angelic hymn first sung at Bethlehem, _Gloria in Excelsis Deo_. In this way does the poet teach us the lesson that both Purgatory proper and the penitential discipline of life give us a peace wholly in contrast with the uproar of sin whether heard in the halls of conscience or in the eternal Hereafter. "How different are those openings from those in Hell," he says, "for here we enter through songs and down there through fierce wailings" (XII, 112). Although our poet, imbued with the Catholic doctrine, teaches that intercessory prayer helps the soul to shorten its term in Purgatory--a doctrine bound up with the doctrine of the Communion of Saints--it must never be forgotten that Dante is a Catholic preacher when he insists that personal effort aided by God's grace, is the thing of supreme importance in the matter of salvation and purification. Neither lip-sorrow nor the sacraments themselves unless accompanied by true sorrow and repentance, can profit the soul. "He cannot be absolved who doth not first repent, nor can he repent the sin and will it at the same time, for this were contradiction to which reason cannot assent" (Inf., XXVII, 118.) Prayer can help the soul struggling in life or in Purgatory proper, but the assistance derived from prayer can never do away with the necessity of personal penance. "Conquer thy panting with the soul that conquers every battle if with its heavy body it sinks not down." Let us now hear how Dante sings "of that second realm in which the human soul is purified and becomes worthy to ascend to Heaven" (I, 5). Coming out of the blackness of Hell just before dawn on Easter Sunday, Virgil and Dante are entranced at the beautiful scene before them. Through a cloudless sky of that deep blue for which the sapphire is noted, shines Venus, the morning star; in the south appear four wonderful stars of still greater brilliancy, seen before only by our first parents. "Sweet sheen of oriental sapphire hue That, mantling in the aspect calm and bright Of the pure air, to the primal circle grew, Began afresh to give my eyes delight Soon as I issued from the deathful air That had cast sadness o'er my mind and sight, The beauteous planet that for love takes care Was making the East laugh through all its span, Veiling the Fish, that in its escort were Turned to the right, I set my mind to scan The other pole; and four stars met my gaze Ne'er seen before, except by primal man Heaven seemed rejoicing in their flaming rays."