This argument does not attempt to demonstrate the existence of a First Ground directly. It shows that assuming its non-existence leads to contradiction within the logic of justification.
Diagram — Metalogical Inconsistency of the Denial of a First Ground
1. Premise — The Denial
Assume ¬∃G: there is no first ground. Then for every proposition P there exists another ground Gn+1 such that
— meaning every statement depends on another, forming an infinite regress of justification.
2. Meta-logical Observation
The very statement ¬∃G is itself a proposition Q. If Q is true, it too requires a ground within the same structure:
But by hypothesis, no terminal G exists. Therefore Q’s own justification is non-terminating, i.e. infinite.
An infinitely deferred justification cannot yield a determinate truth value in finite reasoning. Hence, Q cannot be known or asserted as true without violating the very condition it posits.
3. Contradiction
To assert ¬∃G as true presupposes some ground Gq that validates it, while the premise denies the existence of any such G. Therefore:
but ¬∃G forbids ∃Gq ⇒ ⊥
The statement negates the very precondition of its own truth. It is self-invalidating — a meta-logical contradiction.
4. Conclusion
The denial of a First Ground (¬∃G) collapses into incoherence because its assertion necessarily presupposes the grounding it denies. It cannot be held consistently within any finite or meaningful system of reasoning. Thus, while the argument does not yet affirm what G is, it shows that the structure of logic itself forbids its complete absence.