IB Philosophy 1.1.1 Personal Identity Notes

The Question of Personal Identity

1. The question "Who am I?" is one of philosophy's oldest and most pressing puzzles, sitting at the heart of Unit 1's broader inquiry into what it means to be human.
2. Personal identity as a philosophical problem asks not just how we recognise people in everyday life, but what metaphysically makes a person: what kind of thing we are at our most basic level.
3. The question splits into two sub-problems:
   1. the synchronic question ("What makes me a person right now?") and
   2. the diachronic question ("What makes me the same person I was ten years ago?").
   3. The diachronic version generates the most controversy.
4. Answers carry deep practical implications: they shape how we think about moral responsibility, punishment, survival after death, and the coherence of long-term personal projects.
5. One influential approach is the physical continuity view, which holds that personal identity consists in the continuity of the same biological organism.
   1. Its difficulty: cells are constantly replaced, yet we say the person persists. This view is examined more fully in 1.1.2 alongside the problem of persistence over time.
6. A rival tradition emphasises psychological continuity: what makes you the same person is not your body but your mind (your memories, beliefs, desires, and personality), tying identity to consciousness rather than to matter.
7. A third tradition, rooted in Buddhist philosophy, takes a more radical line: it denies that there is any persisting self to identify at all.
   1. On this view, "personal identity" is not a real metaphysical fact about a thing called a self.
   2. It is simply a conventional label for a constantly changing process, much as we call a river by one name even though the water in it is always different.
8. Aristotle, in De Anima, argued that the soul (psyche) is the form of the body: the organising principle that makes the body a living human being, not a separate ghost inside the machine.
   1. This gave an early account of the person as a unified body-soul composite, and it influenced later thinkers including Ibn Rashd (Averroes), who worked within the Aristotelian tradition.
9. These debates connect directly to nearby topics in this unit: the persistence of identity over time is examined in 1.1.2 Identity Over Time, while how culture shapes our sense of who we are is explored in 1.1.3 Cultural Identity.
10. Understanding what sort of metaphysical things we are is not just an abstract exercise.
    1. It conditions every answer we give to questions about human dignity, rights, and relationships, making it foundational to the whole study of being human.

Locke's Memory Theory: Consciousness as the Ground of Identity

Locke's Memory Criterion

1. John Locke, writing in An Essay Concerning Human Understanding (1689), offered the most influential early account of personal identity grounded in consciousness and memory rather than in substance or body.
2. Locke drew a crucial distinction between three concepts: the identity of a substance (a physical atom), the identity of a man (a biological organism), and the identity of a person (a self-conscious rational being capable of moral accountability).
3. For Locke, personhood is defined by consciousness: the ability to look back through memory and recognise past experiences as your own.
   1. In his words: "as far as this consciousness can be extended backwards to any past action or thought, so far reaches the identity of that person."
4. This means memory is the criterion of personal identity: you are the same person as your ten-year-old self because you can remember (directly or via overlapping chains) the experiences of that child, making consciousness, not body, the metaphysical ground of identity.
5. A key implication: personal identity is separable from bodily identity.
   1. In the famous prince-and-cobbler thought experiment, Locke argues that if a prince's consciousness were transplanted into a cobbler's body, the prince's person would follow the consciousness, not stay with the original body.
6. Locke's theory has direct moral significance: we hold people responsible for past actions because memory connects them to those actions.
   1. Punishment makes sense only if the punished person is psychologically continuous with the wrongdoer.

Objections: Reid, Transitivity, and Parfit

1. Thomas Reid raised a powerful objection to Locke's memory criterion: it is circular, because to identify a memory as mine I must already know who I am, so memory cannot be what constitutes identity.
   1. Reid's Brave Officer argument and its full implications for Locke's theory are examined in 1.1.2.
2. Reid's Brave Officer argument illustrates the problem: an old general remembers his exploits as a young officer, and the young officer remembered being flogged as a schoolboy, but the general cannot recall the flogging.
3. By Locke's criterion, the general is the officer and the officer is the boy, yet the general is not the boy.