Beyond the PSR: A Necessary Entity from a Transmundane Condition of Possibility

Traditional cosmological arguments are often thought to rely fatally on the Principle of Sufficient Reason (PSR). This paper develops a contingency argument that does not. We adopt a two-sorted first-order logic with predicates for world-membership and symmetric accessibility between possible worlds. Within this framework, we formulate four axioms, each verified to be consistent and independent both from one another and from the PSR. We provide philosophical justification for each axiom. Then, we demonstrate that, if the empty world does not access any non-empty world, the existence of a necessary entity follows from the well-foundedness of a transmundane material condition of possibility.