As stated before, ontology was the first brand service from metaphysics. Ontology is the philosophical study of being in general, it is different from epistemology because it does not question the nature of ‘reality’ but rather asks ‘does reality even exists?’. It was called “first philosophy” by Aristotle in his 5th book of Metaphysics. The Latin term ontologia – meaning science of being – was first coined in 1606 by the German philosopher Jacob Lorhardus in his work Ogdoas Scholastica.
A typical ontological inquiry is followed by a cluster of philosophers validating the existence of some category of object (realists) – note that in the subject of ontology, philosophers categorize objects based on their properties – while from a different standpoint another cluster denies and debates this objects nature of existence (antirealists). Historically, these categories have included ideals, abstract forms, universals, immaterial minds, a mind-independent world, possible but not actual objects, essences, free will, and God. A considerable section of early philosophy in its gist is actually a series of ontological disputes.