for this word by misapplication or metaphor is transferred from the body to the soul; but they have simply thought it to be that small part itself of the body, which we see when the inward parts are rent asunder. Others, again, have believed the soul to be made up of very minute and individual corpustules, which they call atoms, meeting in themselves and cohering. Others have said that its substance is air, others fire. Others have been of opinion that it is no substance at all, since they could not think any substance unless it is body, and they did not find that the soul was body; but it was in their opinion the tempering together itself of our body, or the combining together of the elements, by which that flesh is as it were conjoined. And hence all of these have held the soul to be mortal; since, whether it were body, or some combination of body, certainly it could not in either case continue always without death. But they who have held its substance to be some kind of life the reverse of corporeal, since they have found it to be a life that animates and quickens every living body, have by consequence striven also, according as each was able, to prove it immortal, since life cannot be without life.
For as to that fifth kind of body, I know not what, which some have added to the four well-known elements of the world, and have said that the soul was made of this, I do not think we need spend time in discussing it in this place. For either they mean by body what we mean by it, viz., that of which a part is less than the whole in extension of place, and they are to be reckoned among those who have believed the mind to be corporeal: or if they call either all substance, or all changeable substance, body, whereas they know that not all substance is contained in extension of place by any length and breadth and height, we need not contend with them about a question of words.
10. Now, in the case of all these opinions, any one who sees that the nature of the mind is at once substance, and yet not corporeal, -- that is, that it does not occupy a less extension of place with a less part of itself, and a greater with a greater, -- must needs see at the same time that they who are of opinion that it is corporeal  do not err from defect of knowledge concerning mind, but because they associate with it qualities without which they are not able to conceive any nature at all. For if you bid them conceive of existence that is without corporeal phantasms, they hold it merely nothing. And so the mind would not seek itself, as though wanting to itself. For what is so present to knowledge as that which is present to the mind? Or what is so present to the mind as the mind itself? And hence what is called "invention," if we consider the origin of the word, what else does it mean, unless that to find out  is to "come into" that which is sought? Those things accordingly which come into the mind as it were of themselves, are not usually said to be found out,  although they may be said to be known; since we did not endeavor by seeking to come into them, that is to invent or find them out. And therefore, as the mind itself really seeks those things which are sought by the eyes or by any other sense of the body (for the mind directs even the carnal sense, and then finds out or invents, when that sense comes to the things which are sought); so, too, it finds out or invents other things which it ought to know, not with the medium of corporeal sense, but through itself, when it "comes into" them; and this, whether in the case of the higher substance that is in God, or of the other parts of the soul; just as it does when it judges of bodily images themselves, for it finds these within, in the soul, impressed through the body.
 Psalm 9. cxi., and cxxxviii., Deuteronomy 6:5, and Matthew 22:37  [The distinction between corporeal and incorporeal substance is one that Augustin often insists upon. See Confessions VII. i-iii. The doctrine that all substance is extended body, and that there is no such entity as spiritual unextended substance, is combatted by Plato in the Theatetus. For a history of the contest and an able defence of the substantiality of spirit, see Cudworth's Intellectual System, III. 384 sq. Harrison's Ed.--W.G.T.S.]  Invenire  Inventa
 [The distinction between corporeal and incorporeal substance is one that Augustin often insists upon. See Confessions VII. i-iii. The doctrine that all substance is extended body, and that there is no such entity as spiritual unextended substance, is combatted by Plato in the Theatetus. For a history of the contest and an able defence of the substantiality of spirit, see Cudworth's Intellectual System, III. 384 sq. Harrison's Ed.--W.G.T.S.]