Definition

1. Noun:
   • The branch of metaphysics dealing with the nature of being and existence: In philosophy, ontology is the study of what exists, the fundamental categories of being, and how entities relate to one another.
   • A formal, structured representation of knowledge: In computer and information science, an ontology is a rigorous framework that defines a set of concepts, categories, and the relationships between them within a specific domain.

Examples of Usage

• Philosophical context:
  • Aristotle's work laid the foundation for Western ontology.
  • The philosopher's primary question was one of ontology: what is the nature of reality?
• Computer science context:
  • The development team created an ontology to standardize data across medical databases.
  • Semantic web technologies rely heavily on well-defined ontologies.

Advanced Usage

• "Formal ontology": In philosophy, a systematic account of existence in terms of a theory of categories. In computer science, an ontology specified in a formal language.
  • The project required the construction of a formal ontology for legal reasoning.
• "Ontological commitment": The acceptance of a specific theory about what exists.
  • By using this scientific framework, we make a certain ontological commitment about the fundamental particles of the universe.

Variants and Related Words

• Ontological (adj): Pertaining to ontology.
  • The debate centered on an ontological difference between the two theories.
• Ontologist (n): A person who studies or develops ontologies.
  • She is an ontologist specializing in biomedical informatics.

Synonyms

• Metaphysics (in the philosophical sense, though broader): The branch of philosophy that deals with the first principles of things, including abstract concepts such as being, knowing, identity, time, and space.
• Knowledge representation (in the computer science sense): A field of artificial intelligence dedicated to representing information about the world in a form that a computer system can utilize.

Related Phrases

• Ontological argument: A philosophical argument for the existence of God, asserting that the very concept of God implies existence.
  • Anselm of Canterbury is famous for his ontological argument.
• Upper ontology: In computer science, a high-level ontology that describes very general concepts which are the same across all knowledge domains.
  • The system was built upon a shared upper ontology to ensure interoperability.

Noun

1. the metaphysical study of the nature of being and existence
2. (computer science) a rigorous and exhaustive organization of some knowledge domain that is usually hierarchical and contains all the relevant entities and their relations