Taesung Han

This paper challenges the widespread assumption that objective, independent, and concrete existence suffices for genuine reality. Focusing on David Lewis’s modal realism, which treats any universe meeting three ontological criteria—concreteness, causal isolation, and absence of external spatiotemporal relations—as fully real, I construct an arbitrary universe satisfying these criteria yet governed by a necessarily false mereological law that undermines the world's foundational structure. This counterexample demonstrates that Lewis’s criteria, while necessary, are not sufficient for a truth-reflecting reality. The analysis presents an internal reductio: either such a universe is real, undermining the link between concrete existence and truth, or Lewis’s sufficiency claim fails. In either case, genuine modal realism cannot secure reality’s truth-reflecting dimension without an additional condition—logical or metaphysical possibility—that Lewis explicitly rejects. The findings reveal intrinsic limits of metaphysical pluralism and highlight the need for criteria beyond mere ontological status to account for genuine reality.