Ante-Nicene Fathers, Vol VII:
Lactantius: Chap. LXX.—The immortality of the soul is confirmed

Chap. LXX.—The Immortality of the Soul is Confirmed.

It may in truth be collected from many arguments that souls are eternal. Plato says that that which always moves by itself, and has no beginning of motion, also has no end; but that the soul of man always moves by itself, and because it is flexible for reflection, subtle for discovery, easy of perception, adapted to learning, and because it retains the past, comprehends the present, foresees the future, and embraces the knowledge of many subjects and arts, that it is immortal, since it contains nothing which is mixed with the contagion of earthly weight. Moreover, the eternity of the soul is understood from virtue and pleasure. Pleasure is common to all animals, virtue belongs only to man; the former is vicious, the latter is honourable; the former is in accordance with nature, the latter is opposed to nature, unless the soul is immortal. For in defence of faith and justice, virtue neither fears want, nor is alarmed at exile, nor dreads imprisonment, nor shrinks from pain, nor refuses death; and because these things are contrary to nature, either virtue is foolishness, if it stands in the way of advantages, and is injurious to life; or if it is not foolishness, then the soul is immortal, and despises present goods, because other things are preferable which it attains after the dissolution of the body. But that is the greatest proof of immortality, that man alone has the knowledge of God. In the dumb animals there is no notion 1601 of religion, because they are earthly and bent down to the earth. Man is upright, and beholds the heaven for this purpose, that he may seek God. Therefore he cannot be other than immortal, who longs for the immortal. He cannot be liable to dissolution, who is connected 1602 with God both in countenance and mind. Finally, man alone makes use of the heavenly element, which is fire. For if light is through fire, and life through light, it is evident that he who has the use of fire is not mortal, since this is closely connected, this is intimately related to Him without whom neither light nor life can exist.  

But why do we infer from arguments that souls are eternal, when we have divine testimonies? For the sacred writings and the voices of the prophets teach this. And if this appears to any one insufficient, let him read the poems of the Sibyls, let him also weigh the answers of the Milesian Apollo, that he may understand that Democritus, and Epicurus, and Dicæarchus raved, who alone of all mortals denied that which is evident. Having proved the immortality of the soul, it remains to teach by whom, and to whom, and in what manner, and at what time, it is given. Since fixed and divinely appointed times have begun to be filled up, a destruction and consummation of all things must of necessity take place, that the world may be renewed by God. But that time is at hand, as far as may be collected from the number of years, and from the signs which are foretold by the prophets. But since the things which have been spoken concerning the end of the world and the conclusion of the times are innumerable, those very things which are spoken are to be laid down without adornment, since it would be a boundless task to bring forward the testimonies. If any one wishes for them, or does not place full confidence in us, let him approach to the very shrine of the heavenly letters, and being more fully instructed through their trustworthiness, let him perceive that the philosophers have erred, who thought either that this world was eternal, or that there would be numberless thousands of years from the time when it was prepared. For six thousand years have not yet been completed, and when this number shall be made up, then at length all evil will be taken away, that justice alone may reign. And how this will come to pass, I will explain in few words.  

Footnotes

Suspicio.  

Cum Deo communis est.