Ontology definitions 1 and 2

I recently came across these two ‘branches’ of Wikipedia that very nicely (in my opinion) clarify the distinction between the modern semantic web / computer science usage of ‘ontology’ and the old philosophical usage:

Ontology (Computer Science usage, e.g. as a data model):

In computer science, an ontology is a data model that represents a domain and is used to reason about the objects in that domain and the relations between them. … Contemporary ontologies share many structural similarities, regardless of the language in which they are expressed. … most ontologies consist of individuals (instances), classes (concepts), attributes, and relations.

Ontology (Philosophical usage)

In philosophy, ontology (from the Greek ὄν, genitive ὄντος: of being (part. of εἶναι: to be) and -λογία: science, study, theory) is the most fundamental branch of metaphysics. It studies being or existence and their basic categories and relationships, to determine what entities and what types of entities exist. Ontology thus has strong implications for conceptions of reality.

VERY useful and concise descriptions, in my view, including some deeper discussion and very nice examples; at the very least worth a 3-minute read of each.

You may disagree with these pages, BUT my informal criterion is that the first should have you saying “ah, of course” and the second should cause your head to spin and/or cause you to reach for (more) alcohol.

Technorati Tags: ontology, definition, philosophy