STRUCTURE.--Dante’s Paradise consists of the nine moving heavens, according to Ptolemaic astronomy, crowned by the tenth motionless and divinest Empyrean heaven, “according to what Holy Church teacheth, who cannot lie” (_Conv._ ii. 3, 4). The nine moving spheres revolve round our globe, the fixed centre of the Universe, each of the lower eight being enclosed in the sphere above itself. The seven lowest are the heavens of the planets: the Moon, Mercury, Venus, the Sun, Mars, Jupiter, Saturn. The eighth or stellar heaven, the sphere of the Fixed Stars or Firmament, is the highest visible region of the celestial world, and to some extent corresponds to the Earthly Paradise in the lower realms. Above this visible firmament, the ninth or Crystalline heaven, the _Primum Mobile_, directs with its movements the daily revolution of all the others. In it nature starts; from it proceed time and motion, with all celestial influence for the government of the world (_Par._ xxvii. 106-120). It is “the royal mantle of all the volumes of the world, which is most fervent and most living in God’s breath, and in His ways” (_Par._ xxiii. 112-114); and it communicates in different degrees some participation in this quickening breath of God to the other sphere which it encloses, and to all the Universe. It moves swiftest of all, from the fervent desire of all its parts to be united to the Empyrean, the spaceless and motionless ocean of Divine love, where God beatifies the saints and Angels in the vision of His Essence. This Empyrean is the true intellectual Paradise, for which the lower heavens are merely sensible preparations. “This is the sovereign edifice of the world, in which all the world is included, and outside of which is nothing; and it is not in space, but was formed only in the First Mind” (_Conv._ ii. 4); “The heaven that is pure light; light intellectual full of love, love of true good full of joy, joy that transcendeth every sweetness” (_Par._ xxx. 39-42). GRADATIONS.--Each of the nine lower spheres represents a step higher in knowledge, in love, in blessedness, until in the true Paradise the soul attains to perfect knowledge, supreme love, and infinite blessedness in union with the First Cause, in the Beatific Vision of the Divine Essence. The ascent is marked by the increased loveliness of Beatrice, as she guides Dante upwards from heaven to heaven; it is marked, too, by gradations in the brilliancy of the blessed spirits themselves, by their ever increasing ardour of charity towards the poet, and by the growing spirituality of the matters discussed in each sphere--veil after veil being drawn aside from the mysteries of the Divine treasure-house.