If there were a plurality of basic substances, each differing in what Diogenes calls their "own proper nature," there could be no interaction between them.
In Quodlibet II, q. 7 Godfrey considers three theories that defend plurality of forms in all material substances, or at least of duality of substantial forms in human beings (Henry of Ghent).
He regards theories that defend plurality of forms in all material substances as more improbable, and Henry's theory of duality of forms in human beings as less improbable.
Taken in contrast to the Aristotelian doctrine that each existent has a single substantial form (ensuring its unity as a substance), "the plurality of forms" doctrine describes the Universal Hylomorphic sense in which each existent has a number of essential forms (and matters).
Here Thomas is relying upon the substantial unity that is obvious to the philosopher to reject a kind of substance plurality, not just soul-body dualism.
But he also links it, via the quotation from Aquinas, to the doctrine of universal hylomorphism.[22] Again, E. A. Synan [1993], p. 236, refers to Aquinas's denial that there can be a plurality of substantial forms in any given substance, and calls it a "rejection of one half of the binarium famosissimum".
Although he does not there say what this "twofold pillar" is, a few pages later (p. 9) he cites "the famosissimum binarium Augustinianum, namely, the hylomorphic composition of all created beings, not only corporeal but also spiritual substances, the angels and the human soul; and plurality of forms in one and the same individual".
Saucedo (manuscript) defends a plural notion of fundamentality, and argues that the plurality of all things is a fundamental plurality, partly to accommodate both gunk and junk.
As a result, universal hylomorphists distinguished between "corporeal" matter, i.e., the matter of physical, sensible objects, and another kind of matter sometimes called "spiritual matter".[5] The theory known as "plurality of forms" is not just the theory that there are typically many forms in a material substance.
The theory of plurality of forms is instead the theory that there is a plurality of substantial forms in a given material substance.
"The AST believes in plurality of ownership.
