ontology

[on-tol-uh-jee] /ɒnˈtɒl ə dʒi/
noun
1.
the branch of metaphysics that studies the nature of existence or being as such.
2.
(loosely) metaphysics.
Origin
1715-25; < Neo-Latin ontologia. See onto-, -logy
Related forms
ontological
[on-tl-oj-i-kuh l] /ˌɒn tlˈɒdʒ ɪ kəl/ (Show IPA),
ontologic, ontologistic
[on-tol-uh-jis-tik] /ɒnˌtɒl əˈdʒɪs tɪk/ (Show IPA),
adjective
ontologist, noun
Examples from the web for ontology
  • Nature, the brute fact of existence the ultimate ontology, prevails.
  • All of the information is arranged in a complicated ontology.
  • Things become easier by abandoning ontology altogether.
  • Metaphysical naturalism represents a particular view about reality and hence belongs to the philosophical field of ontology.
  • To the extent this means banishing from our ontology things that no longer make sense, that seems reasonable.
  • He know how he got is and he knew it had no ontology at all.
  • No interesting question would remain about the ontology of morals--for example, about the metaphysical status of moral facts.
British Dictionary definitions for ontology

ontology

/ɒnˈtɒlədʒɪ/
noun
1.
(philosophy) the branch of metaphysics that deals with the nature of being
2.
(logic) the set of entities presupposed by a theory
Derived Forms
ontological, adjective
ontologically, adverb
Word Origin and History for ontology
n.

"metaphysical science or study of being," 1660s (Gideon Harvey), from Modern Latin ontologia (c.1600), from onto- + -logy.

ontology in Technology

1. A systematic account of Existence.
2. (From philosophy) An explicit formal specification of how to represent the objects, concepts and other entities that are assumed to exist in some area of interest and the relationships that hold among them.
For AI systems, what "exists" is that which can be represented. When the knowledge about a domain is represented in a declarative language, the set of objects that can be represented is called the universe of discourse. We can describe the ontology of a program by defining a set of representational terms. Definitions associate the names of entities in the universe of discourse (e.g. classes, relations, functions or other objects) with human-readable text describing what the names mean, and formal axioms that constrain the interpretation and well-formed use of these terms. Formally, an ontology is the statement of a logical theory.
A set of agents that share the same ontology will be able to communicate about a domain of discourse without necessarily operating on a globally shared theory. We say that an agent commits to an ontology if its observable actions are consistent with the definitions in the ontology. The idea of ontological commitment is based on the Knowledge-Level perspective.
3. The hierarchical structuring of knowledge about things by subcategorising them according to their essential (or at least relevant and/or cognitive) qualities. See subject index. This is an extension of the previous senses of "ontology" (above) which has become common in discussions about the difficulty of maintaining subject indices.
(1997-04-09)