This peerless rhetorical figure is explained in the Banquet, where he says: "As his fellow-citizens come forth to meet him who returns from a long journey even before he enters the gates of his city; so to the noble soul come forth the citizens of the eternal Life." This apparition of the blessed spirits to greet the mystic traveller as he mounts from sphere to sphere has several advantages: "it peoples with hosts of spirits, the immense lonely spaces through which the journey lies"; it affords the poet the opportunity of asking them "many things which have great utility and delight"; it finally gives him a sensible sign of the degree of beatitude which they possess in that realm of many mansions where each is rewarded according to his merit and capacity, the capacity of each spirit being in proportion to its degree of knowledge and love. This is stressed by the poet's representing the apparitions first as faint yet beautiful outlines of human features, then as ascent is made to the other Heavens, the spirits make themselves known by increasing manifestations of light so dazzling finally that the splendor would blind Dante if his vision were not divinely adapted to its supernatural needs. The inequalities of bliss are also symbolized by the sphere in which the spirits appear to him; those in the sphere of the moon, e.g., are less favored than those in the Heaven of Mercury. The inequality of merit, and therefore of reward, is also declared by the difference in both the quickness of the spirits' movement and their clearness of vision into the essence of God. The Empyrean, it is worth while repeating, is the only true Paradise, the nine Heavens being only myths or poetic devices. If spirits are seen there, they have come forth only from the Empyrean and will quickly return there after preparing the poet for the eternal Light of Light. The materials out of which Dante constructs his Paradiso are not, as we are already aware, fantastic images such as he employed for the first two parts of the Divina Commedia, but are things of the spirit, viz., knowledge, beauty, faith, love, joy; and he is aided in making visible those invisible entities of the spiritual life by such intangible things as sound, motion and light. Light, indeed, is one of the leading elements in the Paradiso. The poem begins with a reference to the light of God's glory, and its last line speaks of "the Love which moves the Sun and the other stars." And between this beginning and this end in thirty-three cantiche light is represented not only by degrees of increasing intensity and variety of unlocked for movements but as surrounding the spirits, living flames, and constituting, symbolically, the beatitude of Heaven.