Ontology

Ontology (Gk., ōn, ‘being’, + logos, ‘reflection’). Reflection in philosophy and metaphysics on what truly exists, or on what underlies appearance by way of existent reality. The term was introduced in the 17th cent., when the study of being as being was also called ontosophia. In the continuity of scholasticism, ontology was the term applied to the study of the properties of being as such, in contrast to special metaphysics which studied aspects of being open to experience. W. V. O. Quine made a distinction between ideology and ontology, and between meaning and reference: he argued that what one takes to be existing depends on the values required or allowed by the variables of the language in use, so that there is a necessary relation between language and ontic commitments—hence his claim that ‘to be is to be the value of a variable’. While this might seem to allow virtually any belief to have an ontological correspondent, in fact metaphysical systems (which he called ‘ontic theories’) are tested by their compatibility with science which interacts publicly (and by various other criteria) with the world and universe around us. It then becomes obvious that ontology is intricately related to epistemology (roughly, how do we know what we know?).

Ontologism was a system of philosophy which, applied to theology, claimed that humans know God immediately and directly through natural cognitive abilities: the first act of human cognitive powers is the intuition of God. It was condemned (on the grounds that our knowledge of God can only be analogical) in 1861 and again by Vatican I.