Introduction

The HCAI Ontology replaces OWL and FOAF by providing a framework to represent natural persons through intrinsic qualities such as consciousness, emotions, psychological states, and sociological dynamics, which are not adequately captured as subclasses of owl:Thing. It also supports integration with owl:Thing-based ontologies for tangible entities (e.g., assets, accounts) to ensure interoperability with existing RDF ecosystems. This document provides comprehensive examples to illustrate these distinctions and relationships.

Scope

The HCAI Ontology is designed to:

Namespace

The namespace for the HCAI Ontology is: http://www.w3.org/ns/hcai#

Prefix: hcai:

Ontology Definition

Classes

hcai:NaturalPerson
A human being defined by intrinsic qualities, including consciousness, emotions, and social roles, distinct from owl:Thing or foaf:Person.
hcai:Consciousness
The subjective awareness and self-reflective capacity of a natural person, encompassing perception, intention, and selfhood.
hcai:Soul
The metaphysical essence of a person, representing non-material aspects of identity and existence.
hcai:Emotion
An emotional state (e.g., love, fear, hope) experienced by a natural person.
hcai:PsychologicalState
A mental state or condition (e.g., resilience, anxiety) influencing a person's behavior or perception.
hcai:SociologicalRole
A socially defined role (e.g., caregiver, leader) shaped by cultural or societal context.
hcai:Relationship
An emotional or social bond between natural persons (e.g., friendship, kinship).
hcai:HumanExperience
A lived experience shaping a person's identity (e.g., trauma, cultural immersion).
hcai:ValueBelief
A deeply held belief or value (e.g., compassion, justice) guiding a person's actions.
hcai:TangibleEntity
A subclass of owl:Thing for tangible objects or resources (e.g., assets, accounts) owned or interacted with by a hcai:NaturalPerson.

Properties

hcai:hasConsciousness
Links a hcai:NaturalPerson to their hcai:Consciousness.
Domain: hcai:NaturalPerson
Range: hcai:Consciousness
hcai:hasSoul
Links a hcai:NaturalPerson to their hcai:Soul.
Domain: hcai:NaturalPerson
Range: hcai:Soul
hcai:experiencesEmotion
Connects a hcai:NaturalPerson to a hcai:Emotion.
Domain: hcai:NaturalPerson
Range: hcai:Emotion
hcai:hasPsychologicalState
Associates a hcai:NaturalPerson with a hcai:PsychologicalState.
Domain: hcai:NaturalPerson
Range: hcai:PsychologicalState
hcai:fulfillsRole
Links a hcai:NaturalPerson to a hcai:SociologicalRole.
Domain: hcai:NaturalPerson
Range: hcai:SociologicalRole
hcai:hasRelationship
Associates a hcai:NaturalPerson with a hcai:Relationship.
Domain: hcai:NaturalPerson
Range: hcai:Relationship
hcai:hasExperience
Links a hcai:NaturalPerson to a hcai:HumanExperience.
Domain: hcai:NaturalPerson
Range: hcai:HumanExperience
hcai:holdsBelief
Connects a hcai:NaturalPerson to a hcai:ValueBelief.
Domain: hcai:NaturalPerson
Range: hcai:ValueBelief
hcai:ownsEntity
Links a hcai:NaturalPerson to a hcai:TangibleEntity (e.g., asset, account).
Domain: hcai:NaturalPerson
Range: hcai:TangibleEntity
hcai:emotionType
Specifies the type of an hcai:Emotion (e.g., "love", "anger").
Domain: hcai:Emotion
Range: rdfs:Literal
hcai:psychologicalStateType
Specifies the type of a hcai:PsychologicalState (e.g., "resilience", "depression").
Domain: hcai:PsychologicalState
Range: rdfs:Literal
hcai:roleType
Specifies the type of a hcai:SociologicalRole (e.g., "parent", "mentor").
Domain: hcai:SociologicalRole
Range: rdfs:Literal
hcai:relationshipType
Specifies the type of a hcai:Relationship (e.g., "familial", "professional").
Domain: hcai:Relationship
Range: rdfs:Literal
hcai:experienceType
Specifies the type of a hcai:HumanExperience (e.g., "trauma", "enlightenment").
Domain: hcai:HumanExperience
Range: rdfs:Literal
hcai:beliefType
Specifies the type of a hcai:ValueBelief (e.g., "justice", "empathy").
Domain: hcai:ValueBelief
Range: rdfs:Literal

Axioms

Examples: Human-Centric Concepts

These examples illustrate human factors (consciousness, sociology, psychology, etc.) that are not adequately represented as subclasses of owl:Thing due to their intrinsic, non-tangible nature. 

@prefix hcai:  .
@prefix ex:  .

# Example 1: Consciousness and Self-Reflection
ex:Jamal a hcai:NaturalPerson ;
  hcai:hasConsciousness ex:JamalConsciousness ;
  hcai:hasSoul ex:JamalSoul ;
  hcai:hasExperience ex:JamalEnlightenment .

ex:JamalConsciousness a hcai:Consciousness ;
  hcai:description "Jamal's awareness of his purpose and identity after meditation" .

ex:JamalSoul a hcai:Soul ;
  hcai:description "Jamal's metaphysical essence, shaped by his spiritual journey" .

ex:JamalEnlightenment a hcai:HumanExperience ;
  hcai:experienceType "Spiritual Awakening" ;
  hcai:description "Jamal's transformative retreat in 2024" .

# Example 2: Emotions and Psychological State
ex:Mia a hcai:NaturalPerson ;
  hcai:experiencesEmotion ex:MiaJoy ;
  hcai:hasPsychologicalState ex:MiaResilience .

ex:MiaJoy a hcai:Emotion ;
  hcai:emotionType "Joy" ;
  hcai:context "Celebrating a family milestone" .

ex:MiaResilience a hcai:PsychologicalState ;
  hcai:psychologicalStateType "Resilience" ;
  hcai:description "Mia's ability to recover from personal loss" .

# Example 3: Sociological Role and Relationship
ex:Priya a hcai:NaturalPerson ;
  hcai:fulfillsRole ex:PriyaCaregiver ;
  hcai:hasRelationship ex:PriyaSiblingBond ;
  hcai:holdsBelief ex:PriyaCompassion .

ex:PriyaCaregiver a hcai:SociologicalRole ;
  hcai:roleType "Caregiver" ;
  hcai:context "Priya's role in supporting her elderly parents" .

ex:PriyaSiblingBond a hcai:Relationship ;
  hcai:relationshipType "Familial" ;
  hcai:hasParticipant ex:Ravi ;
  hcai:description "Priya's close bond with her brother Ravi" .

ex:PriyaCompassion a hcai:ValueBelief ;
  hcai:beliefType "Compassion" ;
  hcai:description "Priya's belief in empathetic action" .

ex:Ravi a hcai:NaturalPerson .

Examples: Tangible Entities (Extending owl:Thing)

These examples show how tangible entities (e.g., assets, accounts) can be represented using hcai:TangibleEntity, a subclass of owl:Thing, to integrate with the HCAI Ontology. 

@prefix hcai:  .
@prefix owl:  .
@prefix ex:  .

# Example 1: Asset Ownership
ex:Jamal a hcai:NaturalPerson ;
  hcai:ownsEntity ex:JamalCar .

ex:JamalCar a hcai:TangibleEntity , owl:Thing ;
  hcai:description "Jamal's electric vehicle purchased in 2025" ;
  hcai:entityType "Physical Asset" .

# Example 2: Financial Account
ex:Mia a hcai:NaturalPerson ;
  hcai:ownsEntity ex:MiaBankAccount .

ex:MiaBankAccount a hcai:TangibleEntity , owl:Thing ;
  hcai:entityType "Financial Account" ;
  hcai:description "Mia's savings account at a cooperative bank" .

# Example 3: Digital Asset
ex:Priya a hcai:NaturalPerson ;
  hcai:ownsEntity ex:PriyaDigitalPortfolio .

ex:PriyaDigitalPortfolio a hcai:TangibleEntity , owl:Thing ;
  hcai:entityType "Digital Asset" ;
  hcai:description "Priya's collection of digital artworks on a blockchain" .

Comparison with OWL and FOAF

OWL's owl:Thing is too generic to capture the nuanced, intrinsic qualities of human beings, such as consciousness, soul, or psychological states. FOAF's foaf:Person focuses on social metadata (e.g., foaf:name, foaf:knows), neglecting deeper human factors. HCAI introduces classes like hcai:Consciousness, hcai:Soul, and hcai:ValueBelief to model these aspects. For tangible entities, HCAI integrates with owl:Thing via hcai:TangibleEntity, enabling compatibility with existing RDF systems while prioritizing human-centric semantics.

Conformance

The HCAI Ontology is a standalone vocabulary, independent of OWL and FOAF, but compatible with RDF and RDFS. Implementations should use reasoning engines supporting the defined classes, properties, and axioms. Tangible entities leverage owl:Thing for interoperability with existing ontologies.

Acknowledgments

This unofficial proposal by the W3C Human-Centric AI Community Group aims to redefine how AI systems represent natural persons, replacing OWL and FOAF with a human-focused ontology while supporting integration with tangible entities.