Abstract

Before being able to answer key practical questions dependent on a criterion of personal identity (e.g., am I justified in anticipating surviving the death of my body?), we must first determine which general approach to the issue of personal identity is more plausible, reductionism or non-reductionism. While reductionism has become the more dominant. approach amongst philosophical theorists over the past thirty years, non-reductionism remains an approach that, for all these theorists have shown, could very well still be true. My aim in this paper is to show that non-reductionism is actually either irrelevant---with respect to the practical questions we want answered---or logically impossible. In arguing for this conclusion, I draw from a case Derek Parfit has employed---the CombinedSpectrum---and I provide a number of variations to it which ultimately reveal that we have no possible rational recourse other than to become reductionists.