Platonic TAG:
TAG makes far more sense as a Platonic argument. It avoids the awkward turn toward revelation in its second half and makes the least amount if assumptions.
As you'll see, most of it is already Platonic, it's only derails itself when it tries to ground mythical revelation into the fabric of reality.
P1. To argue, think, know, predicate, classify, count, or do science, one must presuppose objective intelligibility.
P2. Objective intelligibility requires real universals: identity, difference, number, truth, logic, essence, relation, and order.
P3. Real universals cannot be finally grounded in mutable matter, private mental states, social convention, or arbitrary language.
P4. Real universals also cannot be finally grounded in causally inert abstract objects, because such objects cannot explain why reality is ordered by them or why minds can know them.
P5. Therefore, universals must be grounded in an eternal, necessary, living Intellect whose thinking is their reality, the Forms being nothing other than universals understood as the self-luminous content of Nous.
P6. This Intellect must articulate both unity and plurality, because intelligibility requires both sameness and difference, and it must itself proceed from a source beyond predication, since unity that is merely one among many cannot ground unity as such.
P7. If ultimate reality is sheer plurality, unity becomes illusion. If ultimate reality is a unity that excludes plurality, plurality becomes illusion. If ultimate reality is brute and non-noetic, reason and truth are not normative at the root but accidental to it.
P8. The Neoplatonic order alone grounds unity and plurality eternally without collapsing either: the One beyond being as superessential source, the eternal Nous as living self-thinking in which the Forms are articulated as one-and-many, and Soul as the mediating principle by which intelligibility descends into and ascends from the cosmos, constituting an eternal Logos, eternal procession, and eternal rational self-knowledge.
Conclusion. Therefore, the Neoplatonic henology, the One, Nous, and the Forms as Nous's self-luminous content, is the only adequate ground for intelligibility, universals, logic, truth, and rational knowledge.
If reality is not grounded in the eternal self-thinking of Nous proceeding from the One, then logic, universals, identity, and truth are either brute accidents, useful fictions, or causally dead abstractions. But the moment you argue, you treat them as objective and binding. Therefore every argument already participates in the Nous it tries to deny, and every act of recognizing intelligibility is already an anagogic ascent toward the One.
P1. To argue, think, know, predicate, classify, count, or do science, one must presuppose objective intelligibility.
P2. Objective intelligibility requires real universals: identity, difference, number, truth, logic, essence, relation, and order.
P3. Real universals cannot be finally grounded in mutable matter, private mental states, social convention, or arbitrary language.
P4. Real universals also cannot be finally grounded in causally inert abstract objects, because such objects cannot explain why reality is ordered by them or why minds can know them.
P5. Therefore, universals must be grounded in an eternal, necessary, rational, living intellect.
P6. This intellect must be the source of both unity and plurality, because intelligibility requires both sameness and difference.
P7. If ultimate reality is pure undifferentiated oneness, plurality becomes illusion. If ultimate reality is sheer plurality, unity becomes illusion. If ultimate reality is impersonal, reason and truth are not personal or normative at the root.
P8. The Christian Triune God alone grounds unity and plurality eternally: one essence, three persons, eternal Logos, eternal relation, eternal rational self-knowledge.
Conclusion. Therefore, the Christian Triune God is the only adequate ground for intelligibility, universals, logic, truth, and rational knowledge.
If reality is not grounded in the eternal Logos of the Triune God, then logic, universals, identity, and truth are either brute accidents, useful fictions, or causally dead abstractions. But the moment you argue, you treat them as objective and binding. Therefore every argument already borrows from the Logos it tries to deny.