This article is about the philosophical meaning of ontology. For the term in computer science, see ontology (computer science).
In philosophy, ontology (from the Greek ων = being and λόγος = word/speech) is the most fundamental branch of metaphysics. It is the study of being or existence as well as the basic categories thereof--trying to find out what entities and what types of entities exist. Ontology has strong implications for the conceptions of reality.
Some philosophers, notably of the Platonic school, contend that all nouns refer to entities. Other philosophers contend that some nouns are not names of entities but are a kind of shorthand way of referring to a collection (of either objects or events). In this latter view, mind, instead of referring to an entity, instead refers to a collection of mental events experienced by a person; society, instead of referring to an entity, refers to a collection of persons with some shared characteristics; and geometry, instead of referring to an entity, refers to a collection of a specific kind of intellectual activity. The task of any ontology would then be to give an account of which words refer to entities, which do not, why, and what categories result. When this process is applied to nouns such as electrons, energy, promise, happiness, time, truth, causality, and god, ontology becomes fundamental to many branches of philosophy.
Some basic questions
Different philosophers make different lists of the fundamental categories of being; one of the basic questions of ontology is: "What are the fundamental categories of being?"
This highlights one of the problems of the philosophical approach — it relies on continued investigation of categories, and has no clear way to stop asking. Whereas, in theology and library science and artificial intelligence, one typically adopts a relatively stable foundation ontology. This reflects a larger cosmology and probably morals, aesthetic examples or stories, by which foundation priorities have been set. In theology this is derived from a religion and its stable doctrines.
Here are a few more examples of ontological questions:
- What is existence?
- What are physical objects?
- What are the essential, as opposed to merely accidental, attributes of a given object?
- What constitutes the Identity of an object?
- Is it possible to give an account of what it means to say that a physical object exists?
- What are an object's properties or relations and how are they related to the object itself?
- Is existence a property?
- When does an object go out of existence, as opposed to merely changing?
A few quintessential ontological concepts are:
Early history of ontology
The concept of ontology originated in early Greece from Aristotle and Plato. Aristotle described ontology as "the science of being qua being". The word 'qua' means 'with regard to the aspect of'. According to this theory, then, ontology is the science of being with regard to the aspect of being, or the study of beings insofar as they exist. More precisely, ontology concerns determining what categories of being are fundamental and asks whether, and in what sense, the items in those categories can be said to "be".
Subject, relationship, object
"What exists", "What is", "What am I", "What is describing this to me", are all examples of questions about being, and highlight the most basic problem in ontology: finding a subject, a relationship, and an object to talk about. During the Enlightenment the view of René Descartes that "cogito ergo sum" (or "I think therefore I am") had generally prevailed, although Descartes himself did not believe the question worthy of any deep investigation. However, Descartes was very religious in his philosophy, and indeed argued that "cogito ergo sum" proved the existence of God. Later theorists would note the existence of the "Cartesian Other" — asking "who is reading that sentence about thinking and being?" — and generally concluded that it must be God.
This answer, however, became increasingly unsatisfactory in the 20th century as philosophy of mathematics and philosophy of science and even particle physics explored some of the most fundamental barriers to knowing about being.
Body and environment
Schools of subjectivism, objectivism and relativism had existed at various times in the 20th century, and the postmodernists and body philosophers tried to reframe all these questions in terms of bodies taking some specific action in an environment. This relied to a great degree on insights derived from scientific research into animals taking instinctive action in natural and artificial settings — as studied by biology, ecology, and cognitive science.
The processes by which bodies related to environments became of great concern, and the idea of being itself became difficult to really define. What did people mean when they said "A is B", "A must be B", "A was B"...? Some linguists advocated dropping the verb "to be" from the English language, leaving "E Prime", supposedly less prone to bad abstractions. Others, mostly philosophers, tried to dig into the word.
Existentialism considers being to be a fundamental central concept. It is anything that can be said to 'be' in various senses of the word 'be'. The verb to be has many different meanings and can therefore be rather ambiguous. Because "to be" has so many different meanings, there are, accordingly, many different ways of being.
- Ontology. A resource guide for philosophers (http://www.formalontology.it)
- Aristotle's definition of a science of Being qua Being: ancient and modern interpretations (http://www.formalontology.it/being-qua-being.htm)