20. (2) The things that act upon others do not act by approximation and by contact. It is only accidentally when this occurs (that they act by proximity and contact). FOURTH ENNEAD, BOOK THREE. Problems About the Soul. UNION OF THE SOUL AND THE BODY. 21. (20) The hypostatic substance of the body does not hinder the incorporeal in itself from being where and as it wishes; for just as that which is non-extended cannot be contained by the body, so also that which has extension forms no obstacle for the incorporeal, and in relation to it is as nonentity. The incorporeal does not transport itself where it wishes by a change of place; for only extended substance occupies a place. Neither is the incorporeal compressed by the body; for only that which is extended can be compressed and displaced. That which has neither extension nor magnitude, could not be hindered by that which has extension, nor be exposed to a change of place. Being everywhere and nowhere, the incorporeal, wherever it happens to be, betrays its presence only by a certain kind of disposition. It is by this disposition that it rises above heaven, or descends into a corner of the world. Not even this residence makes it visible to our eyes. It is only by its works that it manifests its presence. 22. (21-24) If the incorporeal be contained within the body, it is not contained within it like an animal in a zoölogical garden; for it can neither be included within, nor embraced by the body. Nor is it, compressed like water or air in a bag of skins. It produces potentialities which from within its unity (?) radiate outwards; it is by them that it descends into the body and penetrates it.[331] It is by this indescribable extension of itself that it enters into the body, and shuts itself up within it. Except itself nothing retains it. It is not the body that releases the incorporeal as result of a lesion, or of its decay; it is the incorporeal that detaches itself by turning away from the passions of the body. OF THE DESCENT OF THE SOUL INTO THE BODY, AND OF THE SPIRIT.