Abstract

Multiplicity, i.e., the apparent presence of more than one person associated with one human body, has been controversial since it was first diagnosed 200 years ago. The question of what the correct model is for understanding the phenomenon is still open today. Philosophy can clarify the issue by providing an examination of the assumptions, especially the assumptions about personal identity, upon which each model rests. ;The first chapter of the dissertation provides a brief history of the theoretical controversies around multiplicity and a discussion of the philosophical debate about personal identity as it is relevant to the issues at hand. The second chapter is a discussion of the Multiple Personality Disorder Model of multiplicity. In this chapter I show both the strengths and weaknesses of the MPD model. The third chapter is a discussion of the more recent Dissociative Identity Disorder model of multiplicity. I give the DID model much the same treatment that the MPD model receives in chapter two. There is a focus on the problem of how we construe personal identity and how that affects whether the DID model is viable. The final chapter is a discussion of a model of multiplicity that I am calling the Healthy Multiples model. This model rejects the notion that all multiplicity is pathological and is need of a cure. In this chapter I argue for the viability of the HM model. ;The inclusion of the HM model has implications for how we think about multiplicity. It also has possible implications for the personal identity debate in philosophy