# Ontology
**Domain:** Philosophy / Knowledge Representation / Wiki Architecture
**Doc Type:** Canonical Concept Node
**Maturity:** Foundational
## Definition
An **ontology** specifies the entities, categories and relations a system recognizes. In philosophy it concerns what exists; in information systems it provides an explicit conceptual structure for representing a domain.
## Evolutionary Nexus
[[articles/The Evolutionary Roots of Silicon Valley|The Evolutionary Roots of Silicon Valley]] crosses fossils, genes, institutions, algorithms and persons. Its wiki network therefore needs an ontology that preserves differences among physical object, organism, lineage, model, institution and conscious claimant.
## Rights Context
Recognition depends on categories. If a system has no representational place for a post-biological or nonhuman subject, that subject can be excluded before evidence is evaluated.
## Key Insight
**An ontology is never merely descriptive when institutions use its categories to grant standing or deny existence.**
## Lexical Ontology Context
In [[projects/Ten Years Building a Symbolic Language Engine|Ten Years Building a Symbolic Language Engine]], ontology becomes an operational linguistic layer. [[wiki/WordNet|WordNet]] supplies taxonomic relations, while the project's distinction between a [[wiki/Synset vs Concept Set|synset and a concept set]] separates lexical equivalence from the larger conceptual neighborhood a writer may need to traverse.
This case also demonstrates that ontology and provenance belong together. A relation should remain identifiable as synonymy, taxonomic descent, corpus association, or model inference rather than being flattened into a generic claim of similarity.
## Corpus Governance Context
[[wiki/Bidirectional Ontology|Bidirectional Ontology]] treats this vault's ontology as a developing relationship between concepts and documents. Articles initially supply observations from which concepts are learned; mature concepts later constrain how linked terms may be used. [[wiki/Semantic Elasticity|Semantic Elasticity]] determines how open a concept remains to revision, while [[wiki/Semantic Governance|Semantic Governance]] makes foundational change deliberate rather than accidental.
This governance role is currently maturity-dependent. An evolving node invites discovery and correction. A foundational node exerts stronger constraint but remains revisable through [[wiki/Ontology Evolution|Ontology Evolution]] and, when its dependents are affected, [[wiki/Corpus Recompilation|Corpus Recompilation]].
## See Also
[[wiki/Bidirectional Ontology|Bidirectional Ontology]], [[wiki/Ontology Learning|Ontology Learning]], [[wiki/Ontology Evolution|Ontology Evolution]], [[wiki/Semantic Governance|Semantic Governance]], [[wiki/Semantic Elasticity|Semantic Elasticity]], [[wiki/Encoded Domain Knowledge|Encoded Domain Knowledge]], [[wiki/Recognition Threshold|Recognition Threshold]], [[wiki/Rights|Rights]], [[wiki/Provenance|Provenance]], [[wiki/Knowledge Representation|Knowledge Representation]], [[wiki/Lexical Semantics|Lexical Semantics]]