Obj. To purify fire uses the matter of other things and thus as they burn their nature becomes void
Resp. This fire will cause only purification, not corruption since it is acting by divine power which can prevent the corruption. The matter will simply return to its original and pure state.
St. Augustine = “the world will pass by a change in things, not by their complete destruction
Conclusion
The elements will remain with respect to their substance and proper qualities
But they will be purified from the infection caused by:
1) sins of man and
2) their actions on each other which produce in them unnatural dispositions