Question Two. Whether the World is to be Purged by Fire

40. Secondly I ask whether the world is to be purged by fire.

41. That it is not:

Because then fire, the same fire, would be purged by fire, and so the same thing would purge itself, which is unacceptable.

42. On the contrary:

In Psalm 96.3, “Fire will go before him,” (and it is adduced in Lombard’s text).

I. To the Question

A. Needed Preliminaries

43. I reply:

This conflagration, or purgation by conflagration, which is predicted in many authorities and especially II Peter 3.11-12, is possible for God in many ways, because it is possible for him in every way that does not involve a contradiction.

44. But let inquiry be about what way is more consonant with the nature of the parts of the universe:

It can be that some fire be newly created and of great or small size; and it can be that it is at once in some total breadth and thickness about the earth, and only everywhere by motion round the earth.

45. And both of them can be: namely the first, that fire be generated, and the second, that it be generated in some determinate part above the earth and not everywhere save by motion round the earth. Let enquiry, then, be about these two points, namely production of the fire and the place of the production or conservation or continuation.

B. About the Production of Infernal Fire

46. About the first point: If the fire is posited as created, it is necessary to posit that an equal amount of some other corruptible body is annihilated; or that in the whole corporeal or incorporeal substance a compressing occurs that corresponds to the quantity of this created fire; or it is necessary to posit that this created fire is together with some other body. Also, if it is posited as created, and consequently created from some other thicker body (for fire is the most subtle body among corruptible bodies), it is necessary to say that some other corruptible body is as much compressed as the body from which it is generated is rarer, or that, conversely, a rarer body is converted into a denser one proportionate to this quantity.

47. Therefore, if it were generated from air, either air would have to be converted into water, or water into earth, in as great proportion as would cover the spreading of the generated fire.

48. The thing is plain in an example: For let it be that the whole sphere of air be divided into ten parts, from one of which the fire is generated; and the fire has ten parts each one of which is equal to that [one part of air] from which the whole fire is generated - where will the nine parts [of the remaining air] have their location? Either two bodies must be together, or they must be compressed (or other bodies standing around must be) until they do not fill up the place of nine parts [of air]. But if this happen by the conversion of these nine parts into water, a place for the converted fire will be obtained even though there be no compression of anything else; because those nine [parts of air] do not generate one part of water, but almost do,If ten parts of air are assumed to produce, on conversion, one part of water, then nine parts of air will produce, on conversion, something less than one part of water. ³³ which [one part of water], along with nine previously generated parts of fire (one of the parts is located in the place of the air corrupted into fire), fill the whole place of the ten parts of air. And then there would be a flood of water along with the flaming of the fire, though not in as great a quantity as is the flaming of the fire; for the water would exceed the preexisting water in a part that is a tenth of the generated new fire.Scotus follows the prevailing view, derived from philosophical tradition, that the elements of the physical world are the four of earth, water, air, and fire, with earth being the grossest and fire the subtlest, and with earth at the center and the others round it (in progressive order of subtlety) at different levels or spheres. His example is complex, nevertheless, in expression, but it seems to amount to the following. The whole of the existing air is divided into ten parts and one of these parts is converted into fire. The converted fire itself has ten parts and, being less dense than air, these ten parts together fill up the space of all ten parts of air even though only one part of air was used to generate the ten parts of fire. So, there are nine parts of air remaining that have no place left to exist in. Either then they occupy the same place as the generated fire (so that more than one body is in the same place), or the air is compressed, or other surrounding bodies are, until the nine parts of air no longer fill up the same place as before. If this compression happens by conversion of the nine parts of air into water, and this water fills the same place as one part of air or a bit less (and so the same as one part of fire or a bit less), there will be a flood of water that exceeds any pre-existing water by a part that is equivalent to a tenth part, or a bit less, of the generated fire. The oddity here is that this new water will be in the same place as a tenth part, or almost, of the fire. For the fire converted from one part of air occupies the place of all ten parts of air, so that the nine parts of air not converted into fire and now assumed to be converted into one part or less of water (and so compressed into the equivalent of the place previously occupied by one part or less of air) must occupy the place occupied by one part or less of fire. The flood will indeed be a flood. ³⁴

C. About the Place of Infernal Fire

48. On the second point [n.45]: Since fire only remains outside its sphere in continuous generation (according to the remark of the Philosopher, On Youth and Old Age [5.470a3-5], “it is always coming to be”), how would it persist in any complete sphere round the earth? How also would it purify things, since purification is only by the consuming of something impure, as of vapors or other such mixed bodies, in which there is impurity of air?

D. More Probable Solution

50. Briefly, then, as to the first article, it seems more probable that, just as fire can exist outside its sphere in foreign matter, namely in an ignited body, as burning coal or flame (not that the form of fire is truly in the solid parts, unless it be posited that disparate specific parts together perfect the same matter, which seems unacceptable), so can the vapors existing in the air be ignited by juxtaposition [sc. with the sphere of fire]. And this successive ignition, now of these vapors, now of those (at least for all the air placed above the habitable region of men), can be called the conflagration.

51. And by it is the air well purified, because ignited bodies are converted at once into true and pure air. Since the air is predominant in its region, and since the ignited body, because of mutual contrary qualities in it, namely fire and vapor, resists the air a little (for it also in a way acts for the destruction of itself, but non-ignited vapor was not thus at once convertible by fire into pure air), it is apparent how flame thus has power for purifying gross air. For by the preceding action of an ignited body, and a body having a fiery quality in its watery self and having substantially the quality of water, the gross air is disposed by the containing body so as to be at once converted into what contains it.

And thus is pure air generated, which was not able thus to convert into itself a larger amount of gross vapor.According to the traditional theory of the disposition of the four elements in their pure state, earth is naturally below water which is naturally below air which is naturally below fire. Impure air is impure by containing earthly elements, but when earthly elements (body) are burning, they take on the quality of water (dissipating and becoming fissile, even exuding water), and so rise from the earthly to the watery element, that is, to the element next to the element of air. The previously impure air is now without most of its grosser elements and also now next to the element of air, by contact with which it becomes at once pure air. Thus can fire purify air of its grosser elements so that it becomes pure air. ³⁵

II. To the Initial Arguments

52. To the argument [n.41] I say that fire always remains pure in itself with natural purity, because it is supremely active (such that it would at once convert into itself anything of an extraneous nature that would ascend to that region [of fire]), and because nothing rises by the action of heavenly bodies to the region of pure fire, so as thus to make fire impure. Now it is specifically this impurity from the smoke of sacrifices offered to idols and from infection from the sins of men that does not ascend to the sphere of fire, because neither that smoke nor any other infection from impure acts can ascend to the fire. But this purifying is posited because of the impurity of the air that is contracted from acts of human sin; therefore, it does not follow that the fire purifies itself.