For Dante there must be, also, the Celestial Paradise where man's supernatural destiny will be realized in joys which the eye has not seen and in music which the ear has not heard. His Paradiso has been called the Ten Heavens, but in reality there is in his plan only one Heaven, the Empyrean, the abode of the angels, of the blessed spirits and of God. It is high above the planets and the stars, beyond time and space. The Church has never answered the question: Where is Heaven? Theologians, however, have put forth various opinions. "Some say," writes Father Honthein, that "Heaven is everywhere, as God is everywhere, the blessed being free to move freely in every part of the universe while still remaining with God and seeing Him everywhere." Others hold that Heaven is "a special place with definite limits. Naturally this place is held to exist, not within the earth, but in accordance with the expressions of Scripture, 'without and beyond its limits.'" (Cath. Encycl., VII, 170.) According to Dante's conception, Heaven, being non-spatial and non-temporal, is not a place but a state of spiritual life. As an aid in depicting that state he makes use of a unique literary device. He poetically creates nine Heavens, the Moon, Mercury, Venus, the Sun, Mars, Jupiter, Saturn, the Fixed Stars, the Primum Mobile or First Movement. These, according to the Ptolemaic system which our poet follows, are concentric with the earth, around which as their center they revolve, while the earth remains fixed and motionless. The motion of each of these nine spheres, originally coming from the Primum Mobile, is communicated to it by the love of the angelic guardians, a literal application of the common saying that "love makes the world go around." As a poetic fiction necessary for him to enter finally the true Heaven Dante is required to pass through these nine spheres, the fiction being used by him as an artist to declare the glories of the heavens and as a teacher to inculcate doctrines for the instruction and edification of mankind. In each of the nine Heavens groups of the blessed are represented as coming to meet him "as he returns to God as to the port whence (he) set out when (he) first entered upon the sea of this life."