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Legal ontologies

Historical origins and state of the art

Meritxell Fernández BarreraLaw Department (EUI)

• History of ontologies in legal thought• Approaches to legal knowledge acquisition• Brief state of the art

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History of ontologies in legal thought

Concept of “legal ontology”

• Computational ontologies: Formal specification ofa conceptualisation [Gruber]

• Philosophical Ontology (Metaphysics): study ofbeing qua being [Aristotle]

• Wide sense: network in which nodes are conceptsand arches are semantic relations betweenconcepts

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Historical examples

• Reasons for building legal ontologies:– Consolidation of an autonomous domain– Clarity of legal terms and concepts –better

language better thought-– Systematisation: easier access to legal materials– Scientific rigour: influence of biological

taxonomies

IUS

things actionsPersons

Free Slaves dependent independent In curatorship In guardianship

Freeborn Freedmen

Romancitizens Latins dediticii

In potestate In manu In mancipio

children slaves

GAIUS Institutiones

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IUS

things actionsPersons

GAIUS Institutiones

Subject todivine right

Subject tohuman right

corporeal incorporeal Nec mancipimancipi

sacred

religious

holy public private

Right ofinheritance

Right ofusufruct

Right ofobligation

Lands onItalic soil

slaves

Wildbeasts

Urbanservitudes

XIXth century: the age of legal classifications

• Analytical tradition –Bentham- (common law)– Austin– Hohfeld

• Jurisprudence of concepts (German legal thought)– Savigny– Puchta– Windscheid

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Savigny Persons

Natural Legal

Free

slaves

citizens

latins

peregrini

Sui iuris Alieniiuris

freeborn freedmen

artificialnatural

city village

foundation

association

Puchta Persons

Natural Legal

Slaves Free

Romancitizens

Non Romancitizens

Sui iuris Alieno iuri

subiecti

statuliberi

In libertateesse

freeborn

freedmen

Latin peregrini

Universitas personarum

Universitas bonorum

Intermediateclasses

De facto slavery

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WindscheidReal rights

Servitude Pledge Emphyteusis Right ofsuperficies

Positive NegativePersonal Praedial

Continuous Discontinuous

Usus HabitationUsusfructus

WindscheidThings

simple compound movable

immovable

consumablewhich

wear out

replaceable

non replaceableParts not

connectedphysically

Partsconnectedphysically

Forming a whole

Not forminga whole

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Sacco 2005 Natural reality

objects facts

Non legal Legal facts

Legal acts Other human facts

Natural events

Non transactional

transactional

Financial Non financial

unilateral bilateral

plurilateral

unipersonal

pluripersonal

Some problems with conceptual representation of the legal domain

• Concepts vs. Norms• Open texture of legal concepts• Dynamics of legal concepts

– Version management– Cost of ontology updating

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Knowledge acquisition in Legal Ontology Design

Approaches to legal knowledge

• Ontology: Formalising the meaning of the objectsof a discourse [Antoniou, Van Harmelen]

• The languages/discourses of the law [Tiscornia]:– Language of the legislator– Language of the judges– Language of legal doctrine– Language of legal theory– Language of legal practice [Casanovas]

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Different approaches, differentmethodologies

• Authoritative sources approach:– Corpus of normative texts– NLP– Manual conceptual analysis

• Practical knowledge approach– Ethnographic work (interviews, transcription)– NLP– Manual conceptual analysis

Legal ontologies

State of the art

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Typology

• Degree of abstraction– Foundational or upper– Core– Domain-specific

• Degree of formalisation– Heavyweight– Lightweight

Foundational ontologiesTaxonomy of DOLCE basic categories

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Legal ontologies (until 2002)• LLD [Language for Legal Discourse, L.T. McCarty, 1989]:

– Atomic formula, Rules and Modalities.• NOR [Norma, R.K. Stamper, 1991, 1996]:

– Agents Behavioral invariants, Realizations.• LFU [Functional Ontology for Law, R.W. van Kranlinger; P.R.S. Visser,

1995]: – Normative Knowledge, World knowledge, Responsibility knowledge,

Reactive knowledge and Creative knowledge.• FBO [Frame-Based Ontology of Law, A. Valente, 1995]:

– Norms, Acts and Concepts Descriptions].• LRI-Core Legal Ontology [J. Breuker et al., 2002]:

– Objects, Processes, Physical entities, Mental entities, Agents, Communicative Acts.

• IKF-IF-LEX Ontology for Norm Comparaison [A. Gangemi et al., 2001]: – Agents, Institutive Norms, Instrumental provisions; Regulative norms;

Open-textured legal notions, Norm dynamics.

Casellas 2008http://idt.uab.es/~ncasellas/nuria_casellas_thesis.pdf

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(Casellas 2008)http://idt.uab.es/~ncasellas/nuria_casellas_thesis.pdf

Core legal ontologiesFunctional Ontology of Law (Valente 1995)

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LRI-Core (1st two layers) [Breuker et al.]

Core Legal Ontology

• The CLO provides the general categories of the legal domain that are in principle found in all the legal systems and sub domains, like, for instance, law, legal norm, regulation, legal agent, legal role, among others [Gangemi et al. 2005]

• DOLCE+

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LKIF-Core Ontology [Breuker et al.]

Types vs. Roles of legal ontologies

• Semantic indexing• Conceptual search• Knowledge organisation• Data sharing and interchange• Reasoning, inference drawing

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Ontology of Professional Judicial Knowledge (OPJK) [Casanovas, Casellas

et al.]

MCO: Mediation Core Ontology[Poblet et al.]

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Legal ontologies and approaches to legal knowledge

PositivismConceptual school

Sources: legal textsAuthoritative sources + doctrine

Content, Sources

Legal realismLegal sociologyLegal anthropology

Sources: case law, ethnography

Pragmatic

Legal theoryBasic building blocks of the law

Global

Legal doctrineDomain centeredDomainAbstraction

Law as an evolutionary dynamic system

Complements: fuzzy logics, probability

Complex systemsLimitations of logical formalisms

Legal theoryLegal doctrine

AxiomatisationConceptual

Legal lexicographyLegal translation

Language dependence

TerminologicalFormality,Methodology

Roots in legal thought, methodology

CharacteristicsApproaches to Legal Knowledge

Criteria for distinction

(M. Fernandez-Barrera 2009)

Conclusions

• Historical roots in legal thought that can provideinputs for conceptual analysis in legal ontologydesign

• Controversies in legal theory that have an effecton knowledge acquisition for ontology design

• Variety of legal ontologies according to degree ofabstraction and degree of formality that supportdifferent applications and processes