Motion also receives the demiurgic words, but the orderly distribution which is mingled with a sensible nature, receives the intellectual energy. For the fabrications which exist at the extremity of things require a producing cause of this kind. Every thing therefore which is mutable, which is changed in quality, which is generated and corruptible, is generated from a cause, immoveable indeed according to essence, but moved according to energy. For the motion which is there separated from essence, here produces an essence which is moved. Hence, because that which makes, makes both according to essence and according to energy, both which are as it were woven together, mutation of essence thence derives its progression. Mortal natures therefore require moveable causes, and those that are very mutable, many such causes. For it is impossible that they should remain only begotten; since the mortal genera would not have an existence. It is necessary however, that the mortal nature should exist, in the first place, in order that every thing may have a subsistence which is capable of being generated, viz. both perpetual beings, and those which at a certain time cease to exist. For beyond these is that which in no respect whatever is. In the next place this is necessary, in order that divine natures and being may not be the last of things; since that which is generative of any thing is more excellent and more divine than the thing which it generates. And in the third place it is necessary in order that the world may not be imperfect, not comprehending every thing the causes of which are contained in animal itself. For the ideas which are there, are the causes of every thing whether divine or mortal. Hence Orpheus says that the vivific cause[85] of partible natures, while she remained on high weaving the order of celestials, was a nymph, as being undefiled, and in consequence of this connected with Jupiter, and abiding in her appropriate manners; but that proceeding from her proper habitation, she left her webs unfinished, was ravished, having been ravished was married, and being married generated, in order that she might animate things which have an adventitious life. For the unfinished state of her webs indicates, I think, that the universe is imperfect or unfinished as far as to perpetual animals. Hence Plato says, that the one demiurgus calls on the many demiurgi to weave together the mortal and immortal natures, after a manner reminding us that the addition of the mortal genera is the perfection of the textorial life of the universe, and also exciting our recollection of the divine Orphic fable, and affording us interpretative causes of the unfinished webs [of Proserpine].