[107] [cap.21] But a person may very likely wonder at those who talk about conflagrations and regenerations, not only on account of the arguments which I have just been adducing, by which they are convicted of maintaining erroneous opinions, but also above all other reasons for this one; for since there are four elements of which the world consists, namely, earth, water, air, and fire, why is it that they are to separate fire from all the others, and to affirm that all the others are dissolved into that one? For some one may say, if it is necessary that they should all be resolved into one, why should they not be resolved into air, or water, or earth? For these elements also contain powers of great magnitude; but yet no one has ever said that the world was to pass away into air, or into water, or into earth; so that it would be equally natural to deny that it is resolved into fire.