ABSTRACT
This chapter focuses on the two most paradigmatic reductionist accounts of personal identity: seminal versions of the psychological continuity theory and animalism. Numerical identity appears to require absolute or total qualitative identity. Patients with brain implants report a close interaction between their mental states and the physical substitutes, that is, the cells or the stimulating electrode. The criterion of physical–mental intimacy may be considered in a novel light in the context of the postulated world–brain relation. Jeff McMahan's insistence on minimal functional continuity as the bearer of personal identity—without access to the particular content of mental states such as memories—suggests that what he has in mind is phenomenal continuity. The chapter discusses Thomas Nagel's and McMahan's brain view of personal identity in some detail; and some neurophilosophical reflections on these two approaches. It also discusses seminal versions of both biological and psychological reductionism.
