This is a formal ontology of the structural categories of law, derived from the forthcoming book A Structural Ontology of the Law. Law is treated here not as a body of rules but as a structured region of social reality: a network of norms, powers, roles, obligations, persons, and institutions that bear determinate ontological relations to one another. The ontology renders those categories in formal terms, grounded in the Basic Formal Ontology and validated for consistency by the HermiT reasoner.
What this is
Legal philosophy has long debated what law is: a command, a system of rules, a practice, a set of predictions about what courts will do. A Structural Ontology of the Law takes a different starting point. It asks what kinds of entities law is made of, and how those entities relate. Norms, obligations, powers, rights, duties, legal persons, jurisdictions, institutions, offices, acts, and the relations among them form a structured domain that can be described with the same rigor applied to any other region of reality.
This ontology is the formal counterpart to that project. It is the largest of the BFO-aligned artifacts hosted under this domain — several thousand classes describing the categories of legal structure, each typed under the Basic Formal Ontology and validated for logical consistency. It is offered for several uses:
- As a structural reference for legal theorists and philosophers of law who want to inspect the framework's formal commitments precisely.
- As an instrument for legal informatics, where formal ontologies of legal concepts support reasoning, compliance modeling, and the integration of legal knowledge with other structured data.
- As a comparative object, alongside companion ontologies of philosophical texts at spinoza, leibniz, and geometry of the good.
It does not replace the book. The book makes the arguments; the ontology renders their structural skeleton.
No login required. No queries logged. Pure public artifact.
Contents
Browser
Interactive viewer with BFO tree, source-fragment view, and full-text search across the ontology.
iiMethodology
How the ontology was extracted and validated, the BFO mapping of legal categories, and why source text is shown only as fragments.
iiiCitation
How to cite the ontology and the forthcoming book. BibTeX, Chicago, MLA. The Zenodo DOI.
ivDownload
The OWL artifact itself. Inspect with Protégé, query with rdflib, reason with HermiT.
A note on the source text
The book this ontology formalizes is forthcoming, not yet published. The ontology — the formal structure, the classes, the relations — is released freely. But the book's text remains under copyright and under contract with Palgrave. For that reason, the source-text view shows only short fragments: a keyword plus minimal context, as scholarly provenance markers indicating where in the work each formal commitment arises. These fragments are not a substitute for the book. When the book is published, readers who want the full argument should turn to it.
This is a deliberate design choice, made by the author, who holds the underlying rights and judges these short provenance fragments to be fair scholarly use that promotes rather than substitutes for the forthcoming work.
What this is not
This is not a complete or authoritative statement of the law of any jurisdiction. It is a formal rendering of the structural categories of law as developed in one book by one author. It describes the kinds of things law is made of, not the content of any particular legal system.
Many decisions were made in formalization that another theorist might make differently. The methodology page describes those decisions. The ontology is open to disagreement, criticism, and replacement by better renderings. The reasoner that validated it checked for formal consistency, not for fidelity to the book or for jurisprudential defensibility. Those judgments belong to the reader.
Acknowledgements
The Basic Formal Ontology, on which this work depends, was developed by Barry Smith and colleagues and is documented in Building Ontologies with Basic Formal Ontology (Arp, Smith, and Spear, MIT Press, 2015). The HermiT reasoner is the work of Birte Glimm, Ian Horrocks, Boris Motik, Giorgos Stoilos, and Zhe Wang. The treatment of legal entities draws on the tradition of social ontology, including the work of Adolf Reinach on the a priori foundations of civil law and John Searle on the construction of social reality.
The source text is A Structural Ontology of the Law by David R. Koepsell (forthcoming, Palgrave), copyright the author. The ontology and this site are released under CC-BY 4.0. The book remains under copyright.
The extraction and finalization pipeline is BFO-Agent, an architecture by the same author. Source available at github.com/dkoepsell/bfo-agent. The pilot artifact is archived at Zenodo, DOI 10.5281/zenodo.19713357.