body is the rational
soul, as was proved in the First Part (Q. 75, A. 6). Therefore the
human body is naturally incorruptible.

_I answer that,_ We may speak of any corruptible thing in two ways;
first, in respect of its universal nature, secondly, as regards its
particular nature. A thing's particular nature is its own power of
action and self-preservation. And in respect of this nature, every
corruption and defect is contrary to nature, as stated in _De Coelo_
ii, text. 37, since this power tends to the being and preservation of
the thing to which it belongs.

On the other hand, the universal nature is an active force in some
universal principle of nature, for instance in some heavenly body; or
again belonging to some superior substance, in which sense God is
said by some to be "the Nature Who makes nature." This force intends
the good and the preservation of the universe, for which alternate
generation and corruption in things are requisite: and in this
respect corruption and defect in things are natural, not indeed as
regards the inclination of the form which is the principle of being
and perfection, but as regards the inclination of matter which is
allotted proportionately to its particular form according to the
discretion of the universal agent. And although every form intends
perpetual being as far as it can, yet no form of a corruptible being
can achieve its own perpetuity, except the rational soul; for the
reason that the latter is not entirely subject to matter, as other
forms are; indeed it has an immaterial operation of its own, as
stated in the First Part (Q. 75, A. 2). Consequently as regards his
form, incorruption is more natural to man than to other corruptible
things. But since that very form has a matter composed of contraries,
from the inclination of that matter there results corruptibility in
the whole. In this respect man is naturally corruptible as regards
the nature of his matter left to itself, but not as regards the
nature of his form.

The first three objections argue on the side of the matter; while the
other three argue on the side of the form. Wherefore in order to
solve them, we must observe that the form of man which is the
rational soul, in respect of its incorruptibility is adapted to its
end, which is everlasting happiness: whereas the human body, which is
corruptible, considered in respect of its nature, is, in a way,
adapted to its form, and, in another way, it is not. For we may