◉ The Borrowed Capital Fallacy: Presuppositionalism, Transcendental Overreach, and the Public Ownership of Rational Norms

Presuppositional apologetics often argues that a non-Christian who uses logic, induction, or moral judgment is relying on resources that make sense only within Christianity. The strongest version is not the crude claim that the critic secretly affirms Christian doctrine. It is that Christianity uniquely makes rational practice possible and that denying Christianity while reasoning is therefore inconsistent. That challenge deserves a stronger answer than the observation that people can use rules without knowing their origin. This paper separates five claims that the borrowing metaphor compresses: use of a norm, answerability to it, its metaphysical ground, Christianity's alleged status as its unique ground, and the critic's alleged inferential commitment to Christianity. A generic borrowing charge succeeds as an objection against a critic only if it establishes two bridges. The exclusive-grounding bridge must rule out serious alternative accounts and identify the Christian God-concept rather than generic theism or some thinner metaphysics. The attribution bridge must show that a particular critic's actual commitments, together with the norm used, entail Christianity or contradict its denial. Leading presuppositional strategies may expose local tensions in some worldviews, but the borrowing slogan does not by itself establish either bridge. The result is bounded. It does not show that Christian metaphysics is false, that rational norms lack an ultimate explanation, or that every transcendental argument fails. It shows that metaphysical dependence is not automatically inferential commitment and that a worldview cannot gain exclusive ownership of public rational norms by declaring its rivals unable to use them. Presuppositionalism must identify the norm, defend the modal necessity, compare alternatives reciprocally, and state what would count against its exclusivity claim.