Phaedrus (245-246)

Socrates.And a third kind of possession and madness comes from the Muses. This takes hold upon a gentle and pure soul, arouses it and inspires it to songs and other poetry, and thus by adorning countless deeds of the ancients educates later generations. But he who without the divine madness comes to the doors of the Muses, confident that he will be a good poet by art, meets with no success, and the poetry of the sane man vanishes into nothingness before that of the inspired madmen. All these noble results of inspired madness I can mention, and many more. Therefore let us not be afraid on that point, and let no one disturb and frighten us by saying that the reasonable friend should be preferred to him who is in a frenzy. Let him show in addition that love is not sent from heaven for the advantage of lover and beloved alike, and we will grant him the prize of victory. We, on our part, must prove that such madness is given by the gods for our greatest happiness; and our proof will not be believed by the merely clever, but will be accepted by the truly wise. First, then, we must learn the truth about the soul divine and human by observing how it acts and is acted upon. And the beginning of our proof is as follows: Every soul is immortal. For that which is ever moving is immortal but that which moves something else or is moved by something else, when it ceases to move, ceases to live. Only that which moves itself, since it does not leave itself, never ceases to move, and this is also the source and beginning of motion for all other things which have motion. But the beginning is ungenerated. For everything that is generated must be generated from a beginning, but the beginning is not generated from anything; for if the beginning were generated from anything, it would not be generated from a beginning. And since it is ungenerated, it must be also indestructible; for if the beginning were destroyed, it could never be generated from anything nor anything else from it, since all things must be generated from a beginning. Thus that which moves itself must be the beginning of motion. And this can be neither destroyed nor generated, otherwise all the heavens and all generation must fall in ruin and stop and never again have any source of motion or origin. But since that which is moved by itself has been seen to be immortal, one who says that this self-motion is the essence and the very idea of the soul, will not be disgraced.

Socrates. For every body which derives motion from without is soulless, but that which has its motion within itself has a soul, since that is the nature of the soul; but if this is true,— that that which moves itself is nothing else than the soul,—then the soul would necessarily be ungenerated and immortal. Concerning the immortality of the soul this is enough; but about its form we must speak in the following manner. To tell what it really is would be a matter for utterly superhuman and long discourse, but it is within human power to describe it briefly in a figure; let us therefore speak in that way. We will liken the soul to the composite nature of a pair of winged horses and a charioteer. Now the horses and charioteers of the gods are all good and of good descent, but those of other races are mixed; and first the charioteer of the human soul drives a pair, and secondly one of the horses is noble and of noble breed, but the other quite the opposite in breed and character. Therefore in our case the driving is necessarily difficult and troublesome. Now we must try to tell why a living being is called mortal or immortal. Soul, considered collectively, has the care of all that which is soulless, and it traverses the whole heaven, appearing sometimes in one form and sometimes in another; now when it is perfect and fully winged, it mounts upward and governs the whole world; but the soul which has lost its wings is borne along until it gets hold of something solid, when it settles down, taking upon itself an earthly body, which seems to be self-moving, because of the power of the soul within it; and the whole, compounded of soul and body, is called a living being, and is further designated as mortal. It is not immortal by any reasonable supposition, but we, though we have never seen or rightly conceived a god, imagine an immortal being which has both a soul and a body which are united for all time. Let that, however, and our words concerning it, be as is pleasing to God; we will now consider the reason why the soul loses its wings. It is something like this. The natural function of the wing is to soar upwards and carry that which is heavy up to the place where dwells the race of the gods. More than any other thing that pertains to the body it partakes of the nature of the divine. But the divine is beauty, wisdom, goodness, and all such qualities; by these then the wings of the soul are nourished and grow, but by the opposite qualities, such as vileness and evil, they are wasted away and destroyed.