Soul and Individuation

For Aristotle, Soul and Body are inseparable, i. e. they are related as form-matter, and, hence, are correlative.  In contrast, in Medieval Theology, it is seemingly unanimously held that Soul can survive the death of Body, an agreement that transcends a significant dispute regarding the nature of Soul--whether there are many souls, or one.  Equivalently, the dispute is whether, prior to incarnation, souls are already differentiated, or, soul is one, becoming differentiated only as it is distributed into distinct bodies.  The former thesis seems predominant in contemporary culture, i. e. even the 'rugged individual' is a secularized vestige of it, though the statement 'we are all the same inside', expresses the one-soul thesis.  While Augustine does not address the topic explicitly, his regular use of the definite article in conjunction with 'soul' suggests that he believes that a plurality of souls exist.  In contrast, Aquinas' association of Individuation with Matter seems to commit him to the view that only one soul exists.  Now, the passage at Genesis 2:7, in which God creates Adam by breathing life into dust, seems to support Aquinas, i. e. God's breath would seem to be one and the same on its various occasions.  On the other hand, while Aquinas is traditionally classified as an 'Aristotelian', his thesis that an incorporeal soul exists, is not.