Nicene and Post-Nicene Fathers, Vol. II:
City of God: Chapter 2

Chapter 2.—Of that Death Which Can Affect an Immortal Soul, and of that to Which the Body is Subject.

But I see I must speak a little more carefully of the nature of death.  For although the human soul is truly affirmed to be immortal, yet it also has a certain death of its own.  For it is therefore called immortal, because, in a sense, it does not cease to live and to feel; while the body is called mortal, because it can be forsaken of all life, and cannot by itself live at all.  The death, then, of the soul takes place when God forsakes it, as the death of the body when the soul forsakes it.  Therefore the death of both—that is, of the whole man—occurs when the soul, forsaken by God, forsakes the body.  For, in this case, neither is God the life of the soul, nor the soul the life of the body.  And this death of the whole man is followed by that which, on the authority of the divine oracles, we call the second death.  This the Saviour referred to when He said, “Fear Him which is able to destroy both soul and body in hell.” 578   And since this does not happen before the soul is so joined to its body that they cannot be separated at all, it may be matter of wonder how the body can be said to be killed by that death in which it is not forsaken by the soul, but, being animated and rendered sensitive by it, is tormented.  For in that penal and everlasting punishment, of which in its own place we are to speak more at large, the soul is justly said to die, because it does not live in connection with God; but how can we say that the body is dead, seeing that it lives by the soul?  For it could not otherwise feel the bodily torments which are to follow the resurrection.  Is it because life of every kind is good, and pain an evil, that we decline to say that that body lives, in which the soul is the cause, not of life, but of pain?  The soul, then, lives by God when it lives well, for it cannot live well unless by God working in it what is good; and the body lives by the soul when the soul lives in the body, whether itself be living by God or no.  For the wicked man’s life in the body is a life not of the soul, but of the body, which even dead souls—that is, souls forsaken of God—can confer upon bodies, how little so-ever of their own proper life, by which they are immortal, they retain.  But in the last damnation, though man does not cease to feel, yet because this feeling of his is neither sweet with pleasure nor wholesome with repose, but painfully penal, it is not without reason called death rather than life.  And it is called the second death because it follows the first, which sunders the two cohering essences, whether p. 246 these be God and the soul, or the soul and the body.  Of the first and bodily death, then, we may say that to the good it is good, and evil to the evil.  But, doubtless, the second, as it happens to none of the good, so it can be good for none.

Footnotes

Matt. 10.28.