Ontology

Ontology (formed in the 16th century as Greek ὀντολογία ontología from Ancient Greek ὄν ón 'being' or Ancient Greek τὸ ὄν 'being' and λόγος lógos 'doctrine', i.e. 'doctrine of being' resp. 'doctrine of being') is a discipline of (theoretical) philosophy concerned with the classification of being and the basic structures of reality, e.g. with concepts such as existence, being, becoming and reality. This subject area is largely congruent with what is called "general metaphysics" according to traditional terminology. Ontology involves the questions of how entities are divided into fundamental categories and which of these entities exist at the most fundamental level. This often involves trying to determine what categories or highest kinds there are and how they form a system of categories that provides a comprehensive classification of all entities. The categories commonly proposed include substances, properties, relations, states of affairs, and events. These categories are characterized by fundamental ontological notions, such as individuality and universality, abstractness and concreteness, or possibility and necessity. Of particular interest is the notion of ontological dependence, which determines whether the entities of a category exist at the most fundamental level. Disagreements within ontology are often about whether entities of a particular category exist, and if so, how they relate to other entities.

When used as a countable noun, the terms "ontology" and "ontologies" refer not to the science of being, but to theories within the science of being. Ontological theories can be divided into different types according to their theoretical commitments. Monocategorical ontologies state that there is only one basic category, which is rejected by polycategorical ontologies. Hierarchical ontologies assert that some entities exist at a more fundamental level and that other entities depend on them. Flat ontologies, on the other hand, deny any entity such privileged status.

Ontological questions concerning special subject areas of philosophy are, for example, "What is man?", "Is there a God?" or "Does the world have a beginning?", or in the field of natural sciences "What is matter?", "What is spacetime?", "Are there emergent properties?", "What is life?" or "What is mind?". According to the traditional division of material, these topics fell into the area of "special metaphysics." In some traditional approaches, the focus is on the concept of being and its relation to particular entities. In the natural sciences, "becoming" is of great importance.

Today, in analytical ontology, the terms "ontology" and "metaphysics" are mostly used synonymously. In computer science, formal representation systems have been called "ontologies" since the 1990s, borrowing from the philosophical term.

Term

The term ontology seems to have been first used in German by Rudolf Goclenius (1547-1628). At about the same time there is a reference in Jacob Lorhard (1561-1609), professor in St. Gallen, Switzerland. Johann Georg Walch (1693-1775) defines in his work Philosophisches Lexicon: "Ontology means the doctrine of the end [being], and is a designation by which some recent philosophers understood the science dealing with the end in general and its properties." Walch points out that "others prefer to say ontosophy."

The term "ontology" was first used in its proper sense (doctrine of being) by Rudolf Goclenius in 1613 and by Johannes Clauberg in 1656. Rudolf Goclenius separates ontology and metaphysics.

In the classical philosophical system (which goes back to Christian Wolff, among others) ontology represents a part of metaphysics, namely general metaphysics (metaphysica generalis) in contrast to special metaphysics (metaphysica specialis), which deals with God (natural theology), the soul (natural psychology) and the world (natural cosmology).

With special metaphysics is connected the claim to investigate certain areas of entities on the basis of reason alone (i.e. non-empirically): Natural theology, for example, contrasts with forms of theology based on revelation, on "sacred writings"; natural cosmology contrasts with empirical physics. Typical questions of a special metaphysics are, for example, the problems whether the world has a beginning in time or whether the soul is immortal.

Basic questions of ontology

In the course of history, various phenomena or topics have emerged that are the subject of philosophical or more general scientific discussions, and which can be called the basic questions of ontology:

• the question of existence, which is a characteristic of every being or is questioned as being in itself.
• the problem of totality, of unity in multiplicity, of the (causal) connection of complex entities.
• the distinction between things, constructs, processes, states and events-      
• the dynamic development of material systems, connected with the duality of being and becoming
• the numerical equality or difference, the problem of individuation.
• the question of relationships or relations or structural connections.
• the problem of identity or persistence and change over time.
• the issue of qualitative sameness and difference, the question of the general or the particular, also known as the problem of universals.