Mercury’s Asclepius: On the Soul, 6

On immortality.

...[if it should have] departed from the body: for if it departs pure, it carries nothing corporeal with it. For this reason, a soul so disposed proceeds toward something similar to itself and divine; and when it arrives there, it becomes happy, freed from error, from madness, from fears, and from harsh loves. Hence it is that in his Apology, Socrates confidently says that death is a change and a transmigration of the soul to another place—an admirable gain—and therefore he dies quite willingly. And indeed, it is necessary that what is composite original: compositum; something made of multiple parts or elements that can be separated by its own nature be dissolved. But the soul is not composite; therefore, no dissolution happens to it.

A moving number.

In the 10th book of the Laws, Plato says that the soul is a number which is able to move itself; for he intends for the soul to be immobile according to its substance The essential, unchanging core of its being—namely, by a motion that terminates at the substance—yet accidentally subject to mobility.

Motion of the soul.

For mobility is present in the soul primarily through itself; therefore, it is the first mobile thing and the source of all motions. Indeed, just as among moving things there is a "first mover," so it is plainly the same among things that are moved. This first mover is not an Angel, because according to the Philosophers, an Angel is immobile since it is always the same and understands and wills without the need for discursive reasoning original: discursu; the process of moving from one thought to another to reach a conclusion; nor is it a body, because a body is moved by a quality; nor is it a quality, because quality is moved by the souls of the celestial spheres; therefore, it is the soul. Thus the human soul, as Xenocrates A student of Plato and the third head of the Academy testifies, is a self-moving number—that is, a nature that is manifold and changeable by its own accord. From this it appears that among the Platonists, the forms of other animals are by no means called "souls": both because they depend upon bodies and cannot be said to have their own essence, and because they are called "vivifications" rather than true "lives." Furthermore, just as in fire there are heat, light, and light-footed subtlety, so plainly in the soul there is that vital force, the power of knowing, and the power of desiring. Therefore, just as in fire the internal shining, heating, and rising exist before its heat and light go forth externally, so in the soul these kinds of powers flourish before they appear outwardly. It possesses life internally, therefore, which grants life to the body; from this it follows that the soul cannot depart from itself, and is therefore perpetual and immortal.

Living is the motion of the soul.

Therefore, the soul moves itself because, naturally, it unfolds a vital progression from potentiality to act The transition from having the capacity to do something to actually doing it within itself. For this reason, this motion is spiritual, by which the soul is understood to live in itself before it provides life to the body. And in truth, just as "to understand" is the act of the intellect, so "to live" is the act of life by which the soul lives, or is said to vivify itself. Therefore, Plato’s reasoning can be formed thus: Everything living moves and vivifies itself from within, because indeed all life is a certain motion. But the human soul is of this kind, because it is essentially "life": therefore it moves itself—that is, it unfolds its vital progression from potentiality to act. Since, therefore, the soul always provides living to itself and never deserts itself, there is no doubt that it always lives, and perseveres as immortal and incorruptible.

The soul as the source of motion.

Again, in the Phaedrus, Plato says that the soul is a fountain and a motive principle. A fountain, indeed, because it holds that motion within itself; but a principle, because it pours that motion into the body. The cause of this is that it is moved entirely through itself, and not by another from the outside or the inside. For this reason, Phaedrus says: "Every soul is immortal"—every soul, I say, because as a whole and entire thing, it virtually contains all animations. Thus, the reasoning of the Phaedrus can be stated: That which is moved freely from itself does not depend on matter. But the human soul is of this kind, as has been seen; therefore, it does not depend on matter. That which is so constituted is immortal and perpetual.

The soul is the principle of motion.

Again, that which is the principle of all motions does not begin through motion and a natural agent, nor will it be corrupted through motion. But the rational soul is of this kind: therefore, it cannot be corrupted through motion; for nothing external can violate that from which vital motion arises, except for its Creator. Indeed, if the rational soul is the primary principle which supplies life to itself and internal motion, and never deserts itself, then it will never cease to live. Certainly, if that which is moved must necessarily be moved as long as it adheres to the mover, then where the mover and the moved are the same, they will always be together, and the moved thing will never cease to be moved. Therefore, the human soul will always be immortal and perpetual.

Book of 83 Questions.

Saint Augustine explains Plato's opinion on this [matter]...