The set or inventory of entities that a theory, formalization, or discourse is taken to commit one to accepting as existing, as revealed by the theory's quantificational and categorical vocabulary and the intended interpretation of its expressions.

Principle

Ontological commitment is determined by the entities required to make the theory true under its intended interpretation: quantifiers, singular terms, and categorial predicates, when read literally, indicate commitments to corresponding kinds of entities unless the theory is paraphrased to avoid them.

Demonstration

Illustrative scenario: A formal theory that asserts 'There exists an x such that Number(x) and x = 2' is committed to the existence of the entity(s) that its Number predicate and existential quantifier quantify over; recognizing this guides whether the theory accepts numbers as part of its ontology.

Misapplication

Reading every linguistic mention as ontological commitment: treating reference to fictional characters or hypothetical entities in ordinary speech as committing an ontology conflates mere mention, pretense, or quantifier-free talk with theoretical commitment.

Consequence

Identifying ontological commitments influences metaphysical and methodological choices (what kinds of entities a discipline accepts), affects how theories are compared and paraphrased, and guides reconstruction strategies intended to minimize or explicate commitments.

Reversal

Alternative interpretive strategies (paraphrase, nominalization, parapossibilist re-interpretation, or frameworks that construe quantifiers non-literally) can reduce or alter apparent commitments; thus commitment is sensitive to representational choices and interpretive conventions.

Boundary

Clearly within: formal or theoretical claims that deploy quantifiers and categorical predicates under an explicit interpretation. Boundary case: ordinary-language claims about fictional discourse where commitment depends on pragmatic reading. Clearly outside: purely expressive utterances or indexicals that do not, by themselves, impose ontological claims.

Semantic Tension

Ontological Commitment ↔ Ontological Parsimony/Practical Utility: the desire to minimize commitments (parsimony) competes with theoretical virtues such as explanatory power or pragmatic utility that may favor richer ontologies.

Synthesis

Ontological commitment is not a linguistic reflex but the result of interpretation: to determine what a theory is committed to one must examine formalization choices and interpretive conventions; commitments can be made explicit, revised by paraphrase, or transformed by changing representational frameworks.