Chapter XVI--Analogy of Death and Sleep, and Consequent Argument for the Resurrection.
And let no one think it strange that we call by the name of life a continuance of being which is interrupted by death and corruption; but let him consider rather that this word has not one meaning only, nor is there only one measure of continuance, because the nature also of the things that continue is not one. For if each of the things that continue has its continuance according to its peculiar nature, neither in the case of those who are wholly incorruptible and immortal shall we find the continuance like ours, because the natures of superior beings do not take the level of such as are inferior; nor in men is it proper to look for a continuance invariable and unchangeable; inasmuch as the former are from the first created immortal, and continue to exist without end by the simple will of their Maker, and men, in respect of the soul, have from their first origin an unchangeable continuance, but in respect of the body obtain immortality by means of change. This is what is meant by the doctrine of the resurrection; and, looking to this, we both await the dissolution of the body, as the sequel to a life of want and corruption, and after this we hope for a continuance with immortality,  not putting either our death on a level with the death of the irrational animals, or the continuance of man with the continuance of immortals, lest we should unawares in this way put human nature and life on a level with things with which it is not proper to compare them. It ought not, therefore, to excite dissatisfaction, if some inequality appears to exist in regard to the duration of men; nor, because the separation of the soul from the members of the body and the dissolution of its parts interrupts the continuity of life, must we therefore despair of the resurrection. For although the relaxation of the senses and of the physical powers, which naturally takes place in sleep, seems to interrupt the sensational life when men sleep at equal intervals of time, and, as it were, come back to life again, yet we do not refuse to call it life; and for this reason, I suppose, some call sleep the brother of death,  not as deriving their origin from the same ancestors and fathers, but because those who are dead and those who sleep are subject to similar states, as regards at least the stillness and the absence of all sense of the present or the past, or rather of existence itself and their own life. If, therefore, we do not refuse to call by the name of life the life of men full of such inequality from birth to dissolution, and interrupted by all those things which we have before mentioned, neither ought we to despair of the life succeeding to dissolution, such as involves the resurrection, although for a time it is interrupted by the separation of the soul from the body.