The term ontologia was coined by scholastic writers in the seventeenth century. Rudolf Goclenius, who mentioned the word in 1636, may have been the first user, but the term was such a natural Latin coinage and began to appear so regularly that disputes about priority are pointless. Some writers, such as Abraham Calovius, used it interchangeably with metaphysica; others used it as the name of a subdivision of metaphysics. Johannes Clauberg (1622–1665), a Cartesian, coined instead the term ontosophia. By the time of Jean-Baptiste Duhamel (1624–1706), ontology was clearly distinguished from natural theology. The other subdivisions of metaphysics are cosmology and psychology, from which ontology is also distinguished. Thus, ontologia as a philosophical term of art was already in existence when it was finally canonized by Christian Wolff (1679–1754) and Alexander Gottlieb Baumgarten (1714–1762).

Wolff

For the authors mentioned above, the subject matter of ontology was being as such...