Meta-ontology

Meta-ontology is a term of recent origin first used by Peter van Inwagen in analyzing Willard Van Orman Quine's critique of Rudolf Carnap's metaphysics, where Quine introduced a formal technique for determining the ontological commitments in a comparison of ontologies. Thomas Hofweber, while acknowledging that the use of the term is controversial, suggests that, although strictly construed meta-ontology is a separate metatheory of ontology, the field of ontology can be more broadly construed as containing its metatheory. Advocates of the term seek to distinguish 'ontology', which investigates what there is, from 'meta'-ontology, which investigates what we are asking when we ask what there is.

Jonathan Schaffer argues that there is a different question for meta-ontology to discuss, namely the classification of ontologies according to the hierarchical connections between the objects in them, and the determination of which objects are fundamental and which are derived. He describes three possible types of ontology: flat, that is an array of undifferentiated objects; sorted, that is an array of classified objects; and ordered, that is an array of inter-related objects. Schaffer says Quine's ontology is flat, a mere listing of objects, while Aristotle's is ordered, with an emphasis upon identifying the most fundamental objects.

Amie L. Thomasson says that the Carnap-Quine debate is misplaced when it focuses (as done by Inwagen) upon the analytic-synthetic distinction between entities: "The real distinction instead [that is, instead of the analytic-synthetic distinction] is between existence questions asked using a linguistic framework and existence questions that are supposed to be asked somehow without being subject to those rules—asked, as Quine puts it ‘before the adoption of the given language’." These questions are what Carnap referred to as internal-external distinctions.

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