Objection 1. It would seem that the elements will not be renewed by receiving some kind of brightness. For just as light is a quality proper to a heavenly body, so are hot and cold, wet and dry. qualities proper to the elements. Therefore as the heaven is renewed by an increase of brightness, so ought the elements to be renewed by an increase of active and passive qualities.
Objection 2. Further, rarity, and density are qualities of the elements, and the elements will not be deprived of them at this renewal. Now the rarity and density of the elements would seem to be an obstacle to brightness, since a bright body needs to be condensed, for which reason the rarity of the air seems incompatible with brightness, and in like manner the density of the earth which is an obstacle to transparency. Therefore it is impossible for the elements to be renewed by the addition of brightness.
Objection 3. Further, it is agreed that the damned will be in the earth. Yet they will be in darkness not only internal but also external. Therefore the earth will not be endowed with brightness in this renewal, nor for the same reason will the other elements.
Objection 4. Further, increase of brightness in the elements implies an increase of heat. If therefore at this renewal the brightness of the elements be greater than it is now, their heat will likewise be greater; and thus it would seem that they will be changed from their natural qualities, which are in them according to a fixed measure: and this is absurd.
Objection 5. Further, the good of the universe which consists in the order and harmony of the parts is more excellent than the good of any individual creature. But if one creature be bettered, the good of the universe is done away, since there will no longer be the same harmony. Therefore if the elemental bodies, which according to their natural degree in the universe should be devoid of brightness, were to be endowed with brightness, the perfection of the universe would be diminished thereby rather than increased.
On the contrary, It is written (Apocalypse 21:1): "I saw a new heaven and a new earth." Now the heaven will be renewed by an increase of brightness. Therefore the earth and likewise the other elements will also.
Further, the lower bodies, like the higher, are for man's use. Now the corporeal creature will be rewarded for its services to man, as a gloss of Ambrose seems to say on Romans 8:22, "Every creature groaneth," and a gloss of Jerome on Isaiah 30:26, "And the light of the moon shall be," etc. Therefore the elements will be glorified as well as the heavenly bodies.
Further, man's body is composed of the elements. Therefore the elemental particles that are in man's body will be glorified by the addition of brightness when man is glorified. Now it is fitting that whole and part should have the same disposition. Therefore it is fitting that the elements themselves should be endowed with brightness.
I answer that, Just as there is a certain order between the heavenly spirits and the earthly or human spirits, so is there an order between heavenly bodies and earthly bodies. Since then the corporeal creature was made for the sake of the spiritual and is ruled thereby, it follows that corporeal things are dealt with similarly to spiritual things. Now in this final consummation of things the lower spirits will receive the properties of the higher spirits, because men will be as the angels in heaven (Matthew 22:30): and this will be accomplished by conferring the highest degree of perfection on that in which the human spirit agrees with the angelic. Wherefore, in like manner, since the lower bodies do not agree with the heavenly bodies except in the nature of light and transparency (De Anima ii), it follows that the lower bodies are to be perfected chiefly as regards brightness. Hence all the elements will be clothed with a certain brightness, not equally, however, but according to their mode: for it is said that the earth on its outward surface will be as transparent as glass, water as crystal, the air as heaven, fire as the lights of heaven.
Reply to Objection 1. As stated above (Article 1), the renewal of the world is directed to the effect that man even by his senses may as it were see the Godhead by manifest signs. Now the most spiritual and subtle of our senses is the sight. Consequently all the lower bodies need to be bettered, chiefly as regards the visible qualities the principle of which is light. On the other hand, the elemental qualities regard the touch, which is the most material of the senses, and the excess of their contrariety is more displeasing than pleasant; whereas excess of light will be pleasant, since it has no contrariety, except on account of a weakness in the organ, such as will not be then.
Reply to Objection 2. The air will be bright, not as casting forth rays, but as an enlightened transparency; while the earth, although it is opaque through lack of light, yet by the Divine power its surface will be clothed with the glory of brightness, without prejudice to its density.
Reply to Objection 3. The earth will not be glorified with brightness in the infernal regions; but instead of this glory, that part of the earth will have the rational spirits of men and demons who though weak by reason of sin are nevertheless superior to any corporeal quality by the dignity of their nature. or we may say that, though the whole earth be glorified, the wicked will nevertheless be in exterior darkness, since even the fire of hell, while shining for them in one respect, will be unable to enlighten them in another.
Reply to Objection 4. This brightness will be in these bodies even as it is in the heavenly bodies, in which it causes no heat, because these bodies will then be unalterable, as the heavenly bodies are now.
Reply to Objection 5. The order of the universe will not be done away by the betterment of the elements, because all the other parts will also be bettered, and so the same harmony will remain.
Source: Summa Theologica (New Advent)