On Epistemic Validity and Origin Explanations

Contemporary origin narratives in cosmology and biology are frequently sustained through empirical accommodation, probabilistic appeal, and post hoc mechanism invocation. While such difficulties are commonly treated as open questions awaiting further refinement, this paper maintains that a subset of foundational explanatory steps fail at a prior methodological level. This analysis presents a classificatory distinction between empirical incompleteness, probabilistic exhaustion, and a third category—epistemic invalidity—which characterizes cases in which a proposed explanatory step fails to satisfy the conditions required for generative explanation. In such cases, explanatory continuity is preserved not through derivation but through accommodation. The analysis does not propose alternative origin narratives; instead, it evaluates whether key explanatory steps are physically and methodologically admissible in principle under accepted scientific constraints.