Aristotle associates the form of the human body with the soul and often De Anima iii 5 is interpreted so that Aristotle believed the human soul to be a subsistent form, which means the soul can exist as itself not just as a “something” that “makes” a bulk of matter a human.

Now the question is: How can this interpretation be reconciled with standard strong realism?

What makes a human soul human? It should seem we need to recourse to universals here too, if we need to recourse to universals at all. Somewhat like the third man argument (though without the infinite regress), we need to posit another universal which makes two human souls humans. So how do we get away from this inconsistency, that suddenly forms seem to be exactly similar to particulars?

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    I do not think that a subsistent form means that the soul can exist as itself, that would turn it into a substance. Aquinas goes to pains to deny just that in his interpretation of Aristotle. It rather means that it has causal powers of its own despite being inseparable from its matter. The individuation problem was much discussed by scholastics. Perhaps the most famous solution is by Duns Scotus, who introduced "haecceity" ("thisness"), the qualities of a thing that make it this particular thing, the opposite of essence. Aquinas instead added esse, act of being, to matter/form ontology. – Conifold Aug 23 '18 at 17:47
  • @Conifold Can you recommend a text which goes into the details of what the act of being (esse) means? – wolf-revo-cats Aug 24 '18 at 8:38
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    Kenny's Aquinas on Being is a comprehensive commentary, but see Pasnau's review for perspective. On the soul as subsistent form see Kenny's also Aquinas on Mind, last two chapters especially. Geach's Form and Existence is considered a classic, Pasnau's On What There Is in Aquinas is a recent entry. – Conifold Aug 25 '18 at 5:56
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    Forgot, I really like Maurer's essay on medieval Thomism in an old History of Philosophical Systems. He captures the spirit of the doctrine in a relatively short space and gives the context (e.g. Siger of Brabant reminding Aquinas that Aristotle wrote about form, matter and their composition, not esse). He also has a chapter on Aquinas in his Medieval Philosophy. Geach arrives at the same place, I think, but his exposition is very dry – Conifold Aug 28 '18 at 4:38

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