Select Works And Letters Or Athanasius by Athanasius
Section 33. The soul immortal. Proved by (1) its being distinct from the body, (2) its being the source of motion, (3) its power to go beyond the body in imagination and thought.
But that the soul is made immortal is a further point in the Church's teaching which you must know, to show how the idols are to be overthrown. But we shall more directly arrive at a knowledge of this from what we know of the body, and from the difference between the body and the soul. For if our argument has proved it to be distinct from the body, while the body is by nature mortal, it follows that the soul is immortal, because it is not like the body.2. And again, if as we have shewn, the soul moves the body and is not moved by other things, it follows that the movement of the soul is spontaneous, and that this spontaneous movement goes on after the body is laid aside in the earth. If then the soul were moved by the body, it would follow that the severance of its motor would involve its death. But if the soul moves the body also, it follows all the more that it moves itself. But if moved by itself , it follows that it outlives the body.3. For the movement of the soul is the same thing as its life, just as, of course, we call the body alive when it moves, and say that its death takes place when it ceases moving. But this can be made clearer once for all from the action of the soul in the body. For if even when united and coupled with the body it is not shut in or commensurate with the small dimensions of the body, but often , when the body lies in bed, not moving, but in death-like sleep, the soul keeps awake by virtue of its own power, and transcends the natural power of the body, and as though travelling away from the body while remaining in it, imagines and beholds things above the earth, and often even holds converse with the saints and angels who are above earthly and bodily existence, and approaches them in the confidence of the purity of its intelligence; shall it not all the more, when separated from the body at the time appointed by God Who coupled them together, have its knowledge of immortality more clear? For if even when coupled with the body it lived a life outside the body, much more shall its life continue after the death of the body, and live without ceasing by reason of God Who made it thus by His own Word, our Lord Jesus Christ.4. For this is the reason why the soul thinks of and bears in mind things immortal and eternal, namely, because it is itself immortal. And just as, the body being mortal, its senses also have mortal things as their objects, so, since the soul contemplates and beholds immortal things, it follows that it is immortal and lives for ever. For ideas and thoughts about immortality never desert the soul, but abide in it, and are as it were the fuel in it which ensures its immortality. This then is why the soul has the capacity for beholding God, and is its own way thereto, receiving not from without but from herself the knowledge and apprehension of the Word of God.