Kathleen Wallace in Aeon:
Many philosophers, at least in the West, have sought to identify the invariable or essential conditions of being a self. A widely taken approach is what’s known as a psychological continuity view of the self, where the self is a consciousness with self-awareness and personal memories. Sometimes these approaches frame the self as a combination of mind and body, as René Descartes did, or as primarily or solely consciousness. John Locke’s prince/pauper thought experiment, wherein a prince’s consciousness and all his memories are transferred into the body of a cobbler, is an illustration of the idea that personhood goes with consciousness. Philosophers have devised numerous subsequent thought experiments – involving personality transfers, split brains and teleporters – to explore the psychological approach. Contemporary philosophers in the ‘animalist’ camp are critical of the psychological approach, and argue that selves are essentially human biological organisms. (Aristotle might also be closer to this approach than to the purely psychological.) Both psychological and animalist approaches are ‘container’ frameworks, positing the body as a container of psychological functions or the bounded location of bodily functions.
All these approaches reflect philosophers’ concern to focus on what the distinguishing or definitional characteristic of a self is, the thing that will pick out a self and nothing else, and that will identify selves as selves, regardless of their particular differences.