This chapter explores four approaches to personal identity in terms of numerical identity: person-based accounts, a biological account, a mind-based account, and a social account. We also introduce the concept of narrative identity, which involves a person’s self-conception or self-told story about their life. We argue, first, that person-based accounts and the social account are implausible accounts of numerical identity and, second, that both the mind-based and biological accounts are plausible. This motivates a pluralistic approach to personal identity in the sense that policies and practices should be consistent with both accounts. With these theoretical resources, we turn to three practical issues. First, we neutralize some concerns about human enhancement through biomedical means. Second, we investigate and ultimately vindicate the authority of advance directives in cases of severe dementia. Finally, we address the definition of death and associated questions about unilateral discontinuation of life support and vital organ procurement. Proper resolution of these issues turns primarily on practical considerations other than the nature of death.