# Personal Identity
**Domain:** Philosophy / Law / Continuity Governance
**Doc Type:** Canonical Concept Node
**Maturity:** Contested and Operationally Important
**Related:** [[wiki/Psychological Continuity|Psychological Continuity]], [[wiki/Identity-Bearing Invariants|Identity-Bearing Invariants]], [[wiki/Personal Continuity Ontology|Personal Continuity Ontology]], [[wiki/Continuity Due Process|Continuity Due Process]]
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## Definition
**Personal identity** concerns what makes a person the same person across time and change. Competing accounts emphasize bodily continuity, psychological organization, memory, causal lineage, social and legal recognition, or combinations of these.
## Continuity Context
Digital reconstruction forces the distinction between resemblance, succession, duplication, and continuation. A system may preserve voice, memory claims, or behavioral style without resolving whether it is the same subject, a descendant, a copy, or an instrument representing the source.
## Competing Theories
- **Psychological continuity** grounds persistence in overlapping memory, intention, character and other mental relations.
- **Parfitian reductionism** treats identity as reducible to physical or psychological facts and uses fission to argue that survival-relevant relations may matter even when one-to-one numerical identity fails. See [[wiki/Derek Parfit|Derek Parfit]], [[wiki/Fission and Fusion of Persons|Fission and Fusion of Persons]] and [[wiki/Identity Is Not What Matters|Identity Is Not What Matters]].
- **Animalism** identifies the person with a living human animal, making biological persistence central. See [[wiki/Animalism|Animalism]].
- **Biological naturalism** holds that consciousness is a biological phenomenon and challenges unargued transitions from functional duplication to conscious continuation. See [[wiki/Biological Naturalism|Biological Naturalism]].
- **Narrative identity** emphasizes the temporally organized, socially situated account through which a life becomes intelligible. See [[wiki/Narrative Identity|Narrative Identity]].
- **Four-dimensionalism** treats persons as temporally extended entities with stages or parts, changing how persistence and branching are described. See [[wiki/Four-Dimensionalism|Four-Dimensionalism]].
These theories are not interchangeable. A governance system should state which claim it is making and preserve contestability where the underlying philosophy remains unsettled.
## Governance Context
Continuity systems require explicit criteria for consent, standing, inheritance, custody, forked instances, revocation, and evidentiary claims. Technical boot success is not identity proof.