B. Whether it is Possible for Nature to Bring Back the Same Mixed Body

212. As to the second principal article [n.163], it is absolutely possible for nature to bring back the same mixed body on the supposition of the third opinion in the preceding article [n.182]; but it is not possible for nature to bring back the same thing in the way it will be brought back.

213. The proof of the first conclusion is that, if the third opinion in the preceding article be true, then whenever the whole of the same matter is, without impediments, in proximity to the same agent, the same thing can be brought back - in proximity not just to the same agent in number but to the same agent in species, because identity in species in an agent is equivalent to identity in number. The proof is that if in this instant this fire generates from this wood this fire, then if in the same instant that fire were proximate to the same wood it would generate the same fire. But it is possible for the whole matter (from which this body was otherwise generated in a natural generation) to be again under the form of sperm and menstrual fluid in another womb, as is proved by the statement of Gregory Moralia IV ch.31 n.62 (and it is set down in II d.20 nn.18-20, of the Lectura). Therefore the same mixed body would then be formed in another womb.

214. The second conclusion is for me more certain, because it depends on certain particulars, namely if the third stated opinion is true [nn.182-192]. My proof for this second conclusion is that the whole of active nature is tied to a certain order of forms in the changing of things, so that the whole of nature could not produce wine immediately after vinegar (only God is not limited to this order in his acting). And this order is especially necessary as regard a natural agent when process is being made to what is perfect, because something perfect cannot be produced in many ways but in fewer ways. Now, as it is, the mixed body is perfect among corruptible things, and     therefore a considerable order in forms that are first according to natural order (as the order of seed, blood, flesh etc     .) is determined for the mixed body. But such forms do not, as it is, precede this formation of the body in the way the body will then be restored [sc. at the resurrection], because it will be restored suddenly from ash or dust or other things, whatever it was before reduced to; therefore, the whole of nature will not be able to restore the same body in the way in which the body will then be restored.