The Limits of the Self in Ontological Materialism: On the Indeterminacy of Exclusive Personal Identity

This article examines whether ontological materialism can ground exclusive personal identity over time if it retains the claim that precisely this experiencing subject continues to exist. The starting point is the distinction between qualitative identity and numerical sameness. The exclusivity claim is not defended as a metaphysical truth but used as a test premise: What follows if a materialist self-interpretation seeks to retain it? On the basis of a copying thought experiment and the processual and biologically dynamic structure of the brain, the article shows that qualitative, psychological, and functional continuation is, under materialist premises, in principle multiply realizable. In parity scenarios, relevant criteria of identity can be satisfied more than once without determining which continuation is exclusively numerically identical with the presently experiencing subject. This tension concerns especially the combination of premises consisting of ontological materialism, duplicability, and exclusivity. The article stands close to classical debates on fission, copying, and the reduction of personal identity, especially in Parfit. Its own contribution lies in the examination of a specific architecture of claims: ontological materialism, duplicability, exclusivity, and the ambiguity of material bearer continuity are systematically brought together. Under these conditions, exclusive numerical sameness cannot be secured by additional empirical data. It requires a revision of the claim, a genealogical-organismic determination, the assumption of an epistemically no longer accessible fact of continuation, a non-qualitative additional principle, or the acceptance of indeterminacy. This does not call materialism as a scientific method into question. It limits only its stronger claim to derive the self, as an exclusively identical experiencing subject, entirely from material-functional facts.