Of course, sometimes you get called on it, and sometimes that's probably a good thing because it leads you to find out something interesting, and thus blog more. The other day I said:
Aquinas questioned whether "and thus death came into the world" could be literally accurate, because according to the Aristotelian philosophy creatures do not change in kind, and a change from being mortal to immortal would be a change in kind. (Aquinas argued that the "death" that came into the world was "death" in the spiritual sense often used in scripture, rather than "death" in the biological sense. Thus, Aquinas actually addresses the question that some ask about Genesis and biological evolution: how could there have been evolution before the Fall if death only came into the world after Adam's sin?)A commenter promptly called me on the assertion, and since I was working from a memory (which may have been second hand in the first place) I had to do a little homework before I came up with Summa, Part I, Question 97 where Aquinas deals with the question of man's immortality before the fall.
So here, more precisely, is what Aquinas has to say:
First, on the part of matter--that is to say, either because it possesses no matter, like an angel; or because it possesses matter that is in potentiality to one form only, like the heavenly bodies. Such things as these are incorruptible by their very nature.This actually reminded me a little bit of Tolkien's description of the gift given to the men of Numenor, that so long as they remained virtuous and did not try to grasp immortality, they could choose the time of their own deaths, releasing themselves to God rather than being driven from their bodies by frailty or illness.
Secondly, a thing is incorruptible in its form, inasmuch as being by nature corruptible, yet it has an inherent disposition which preserves it wholly from corruption; and this is called incorruptibility of glory; because as Augustine says (Ep. ad Dioscor.): "God made man's soul of such a powerful nature, that from its fulness of beatitude, there redounds to the body a fulness of health, with the vigor of incorruption."
Thirdly, a thing may be incorruptible on the part of its efficient cause; in this sense man was incorruptible and immortal in the state of innocence. For, as Augustine says (QQ. Vet. et Nov. Test. qu. 19 [Work of an anonymous author, among the supposititious works of St. Augustine): "God made man immortal as long as he did not sin; so that he might achieve for himself life or death." For man's body was indissoluble not by reason of any intrinsic vigor of immortality, but by reason of a supernatural force given by God to the soul, whereby it was enabled to preserve the body from all corruption so long as it remained itself subject to God. This entirely agrees with reason; for since the rational soul surpasses the capacity of corporeal matter, as above explained (76, 1), it was most properly endowed at the beginning with the power of preserving the body in a manner surpassing the capacity of corporeal matter.
This is not the same thing that Aquinas is describing, but it is similar in interesting ways -- with Tolkien's ingrained Catholicity, I suppose it's hardly surprising. Aquinas believed because of Aristotelian natural phiosophy what I would tend to believe based on the evidence of modern science: that it is in the nature of biological creatures to be mortal, and that were an animal nor mortal, it would not be the same species with which we are familiar -- indeed, that an 'immortal horse' is not a horse at all, but a substantially different creature sharing the same appearance of a horse.
However, he needed to square this with the biblical description of Adam and Eve as being immortal until the Fall. His solution is elegant, and I agree with it, though perhaps with one opening for variation. Creatures were still mortal, he concludes, but man's pre-fallen soul was given by God a supernatural degree of control over the body, such that it could preserve the body from all corruption so long as the soul remained in perfect submission to God.
I would assume this left animals mortal, since animals do not possess a rational soul and will infused by God and thus nothing would have preserved them from death or disease. What strikes me as interesting is the question of whether man would have remained bodily immortal, or if eventually he would have voluntarily released soul from body in order to be united with God in heaven. Of course, the Church tells us that after the end of all things we will be reunited with our perfected bodies. Given that man is intended to be constituted of both body and soul, and that man in his unfallen state must have had a perfected body, perhaps there would be no call for an unfallen Adam and Eve to ever leave their bodies. And yet, would there be something lacking in our path to salvation if we never reached the beatific vision of heaven? Did Adam and Eve experience God in the form like the beatific vision, or is that one of the results of the fall, like Christ's saving mission. Is this another benefit of Adam's "felix culpa"?