St. Augustine on Sin and the Body

3.
But if any one says that the flesh is the cause of all vices
and ill conduct, inasmuch as the soul lives wickedly only
because it is moved by the flesh, it is certain he has not
carefully considered the whole nature of man.
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For the corruption of the body, which weighs down the soul,
is not the cause but the punishment of the first sin ;
and it was not the corruptible flesh that made the soul sinful,
but the sinful soul that made the flesh corruptible. And though
from this corruption of the flesh there arise certain incitements
to vice, and indeed vicious desires, yet we must not attribute to
the flesh all the vices of a wicked life, in case we thereby clear
the devil of all these, for he has no flesh.

(From The City of God Book IV: 3)