{ 72} The process of sensation he conceived to be conditioned by an actual emission from the bodies perceived of elements or images of themselves which found access to our apprehension through channels [140] congruous to their nature. But ordering, criticising, organising these various apprehensions was the Mind or _Nous_, which he conceived to be of divine nature, to be indeed an expression or emanation of the Divine. And here has been preserved a strangely interesting passage, in which he incorporates and develops in characteristic fashion the doctrine of transmigration [141] of souls: "There is a decree of Necessity, a law given of old from the gods, eternal, sealed with mighty oaths, that when any heavenly creature (daemon) of those that are endowed with length of days, shall in waywardness of heart defile his hands with sin of deed or speech, he shall wander for thrice ten thousand seasons far from the dwellings of the blest, taking upon him in length of time all manner of mortal forms, traversing in turn the many toilsome paths of existence. Him the aetherial wrath hurries onward to the deep, and the deep spews him forth on to the threshold of earth, and unworn earth casts him up to the fires of the sun, and again the aether hurls him into the eddies. One receives him, and then another, but detested is he of them all. Of such am I also one, an exile and a wanderer from God, a slave to strife and its madness."
Thus to his mighty conception the life of all creation, and not of man only, was a great expiation, an eternal round of punishment for sin; and in the unending flux of life each creature rose or fell in the scale of existence according to the deeds of good or ill done in each successive life; rising sometimes to the state of men, or among men to the high functions of physicians and prophets and kings, or among beasts to the dignity of the lion, or among trees to the beauty of the laurel; or, on the contrary, sinking through sin to lowest forms of bestial or vegetable life. Till at the last they who through obedience and right-doing have expiated their wrong, are endowed by the blessed gods with endless honour, to dwell for ever with them and share their banquets, untouched any more with human care and sorrow and pain.