Objection 1. It would seem that the empyrean heaven was not created at the same time as formless matter. For the empyrean, if it is anything at all, must be a sensible body. But all sensible bodies are movable, and the empyrean heaven is not movable. For if it were so, its movement would be ascertained by the movement of some visible body, which is not the case. The empyrean heaven, then, was not created contemporaneously with formless matter.
Objection 2. Further, Augustine says (De Trin. iii, 4) that "the lower bodies are governed by the higher in a certain order." If, therefore, the empyrean heaven is the highest of bodies, it must necessarily exercise some influence on bodies below it. But this does not seem to be the case, especially as it is presumed to be without movement; for one body cannot move another unless itself also be moved. Therefore the empyrean heaven was not created together with formless matter.
Objection 3. Further, if it is held that the empyrean heaven is the place of contemplation, and not ordained to natural effects; on the contrary, Augustine says (De Trin. iv, 20): "In so far as we mentally apprehend eternal things, so far are we not of this world"; from which it is clear that contemplation lifts the mind above the things of this world. Corporeal place, therefore, cannot be the seat of contemplation.
Objection 4. Further, among the heavenly bodies exists a body, partly transparent and partly luminous, which we call the sidereal heaven. There exists also a heaven wholly transparent, called by some the aqueous or crystalline heaven. If, then, there exists a still higher heaven, it must be wholly luminous. But this cannot be, for then the air would be constantly illuminated, and there would be no night. Therefore the empyrean heaven was not created together with formless matter.
On the contrary, Strabus says that in the passage, "In the beginning God created heaven and earth," heaven denotes not the visible firmament, but the empyrean or fiery heaven.
I answer that, The empyrean heaven rests only on the authority of Strabus and Bede, and also of Basil; all of whom agree in one respect, namely, in holding it to be the place of the blessed. Strabus and Bede say that as soon as created it was filled with angels; and Basil [Hom. ii. in Hexaem.] says: "Just as the lost are driven into the lowest darkness, so the reward for worthy deeds is laid up in the light beyond this world, where the just shall obtain the abode of rest." But they differ in the reasons on which they base their statement. Strabus and Bede teach that there is an empyrean heaven, because the firmament, which they take to mean the sidereal heaven, is said to have been made, not in the beginning, but on the second day: whereas the reason given by Basil is that otherwise God would seem to have made darkness His first work, as the Manicheans falsely assert, when they call the God of the Old Testament the God of darkness. These reasons, however, are not very cogent. For the question of the firmament, said to have been made on the second day, is solved in one way by Augustine, and in another by other holy writers. But the question of the darkness is explained according to Augustine [Gen. ad lit. i; vii.], by supposing that formlessness, signified by darkness, preceded form not by duration, but by origin. According to others, however, since darkness is no creature, but a privation of light, it is a proof of Divine wisdom, that the things it created from nothing it produced first of all in an imperfect state, and afterwards brought them to perfection. But a better reason can be drawn from the state of glory itself. For in the reward to come a two-fold glory is looked for, spiritual and corporeal, not only in the human body to be glorified, but in the whole world which is to be made new. Now the spiritual glory began with the beginning of the world, in the blessedness of the angels, equality with whom is promised to the saints. It was fitting, then, that even from the beginning, there should be made some beginning of bodily glory in something corporeal, free at the very outset from the servitude of corruption and change, and wholly luminous, even as the whole bodily creation, after the Resurrection, is expected to be. So, then, that heaven is called the empyrean, i.e. fiery, not from its heat, but from its brightness. It is to be noticed, however, that Augustine (De Civ. Dei x, 9,27) says that Porphyry sets the demons apart from the angels by supposing that the former inhabit the air, the latter the ether, or empyrean. But Porphyry, as a Platonist, held the heaven, known as sidereal, to be fiery, and therefore called it empyrean or ethereal, taking ethereal to denote the burning of flame, and not as Aristotle understands it, swiftness of movement (De Coel. i, text. 22). This much has been said to prevent anyone from supposing that Augustine maintained an empyrean heaven in the sense understood by modern writers.
Reply to Objection 1. Sensible corporeal things are movable in the present state of the world, for by the movement of corporeal creatures is secured by the multiplication of the elements. But when glory is finally consummaed, the movement of bodies will cease. And such must have been from the beginning the condition of the empyrean.
Reply to Objection 2. It is sufficiently probable, as some assert, that the empyrean heaven, having the state of glory for its ordained end, does not influence inferior bodies of another order--those, namely, that are directed only to natural ends. Yet it seems still more probable that it does influence bodies that are moved, though itself motionless, just as angels of the highest rank, who assist [Infra, 112, 3], influence those of lower degree who act as messengers, though they themselves are not sent, as Dionysius teaches (Coel. Hier. xii). For this reason it may be said that the influence of the empyrean upon that which is called the first heaven, and is moved, produces therein not something that comes and goes as a result of movement, but something of a fixed and stable nature, as the power of conservation or causation, or something of the kind pertaining to dignity.
Reply to Objection 3. Corporeal place is assigned to contemplation, not as necessary, but as congruous, that the splendor without may correspond to that which is within. Hence Basil (Hom. ii in Hexaem.) says: "The ministering spirit could not live in darkness, but made his habitual dwelling in light and joy."
Reply to Objection 4. As Basil says (Hom. ii in Hexaem.): "It is certain that the heaven was created spherical in shape, of dense body, and sufficiently strong to separate what is outside it from what it encloses. On this account it darkens the region external to it, the light by which itself is lit up being shut out from that region. "But since the body of the firmament, though solid, is transparent, for that it does not exclude light (as is clear from the fact that we can see the stars through the intervening heavens), we may also say that the empyrean has light, not condensed so as to emit rays, as the sun does, but of a more subtle nature. Or it may have the brightness of glory which differs from mere natural brightness.
Source: Summa Theologica (New Advent)