(Source: "Meditations for Lent from St. Thomas Aquinas", pp. 46-48 1937 Imp.)
By one man sin entered into this world, and by sin death.
Rom. v. 12.
i. If for some wrongdoing a man is deprived
of some benefit once given to him, that he should
lack that benefit is the punishment of his sin.
Now in man's first creation he was divinely
endowed with this advantage that, so long as his
mind remained subject to God, the lower powers
of his soul were subjected to the reason and the
body was subjected to the soul.
But because by sin man's mind moved away
from its subjection to God, it followed that the
lower parts of his mind ceased to be wholly sub-
jected to the reason. From this there followed
such a rebellion of the bodily inclination against
the reason, that the body was no longer wholly
subject to the soul.
Whence followed death and all the bodily
defects. For life and wholeness of body are bound
up with this, that the body is wholly subject to
the soul, as a thing which can be made perfect is
subject to that which makes it perfect. So it
comes about that, conversely, there are such things
as death, sickness and every other bodily defect,
for such misfortunes are bound up with an
incomplete subjection of body to soul.
2. The rational soul is of its nature immortal,
and therefore death is not natural to man in so far
as man has a soul. It is natural to his body, for
the body, since it is formed of things contrary
to each other in nature, is necessarily liable to
corruption, and it is in this respect that death
is natural to man.
But God who fashioned man is all powerful.
And hence, by an advantage conferred on the
first man, He took away that necessity of dying
which was bound up with the matter of which
man was made. This advantage was however
withdrawn through the sin of our first parents.
Death is then natural, if we consider the matter
of which man is made and it is a penalty, inasmuch
as it happens through the loss of the privilege
whereby man was preserved from dying.
(2-2 164 i.)
3. Sin -original sin and actual sin- is taken
away by Christ, that is to say, by Him who is also
the remover of all bodily defects. He shall quicken
also your mortal bodies, because of his Spirit that
dwelleth in you (Rom. viii. n).
But, according to the order appointed by a
wisdom that is divine, it is at the time which best
suits that Christ takes away both the one and the
other, i.e., both sin and bodily defects.
Now it is only right that, before we arrive at
that glory of impassibility and immortality which
began in Christ, and which was acquired for us
through Christ, we should be shaped after the
pattern of Christ's sufferings. It is then only
right that Christ's liability to suffer should remain
in us too for a time, as a means of our coming to the
impassibility of glory in the way He himself came
(1-2 85 5 ad 2.)