On the entailment account, mutually entailing theories share the same ontological commitments, so T and T* are both committed to Ks.

For a stark illustration of the difference between entailment and quantifier accounts, consider a theory T that contains the single sentence ‘∃x K(x)’ and the theory T* that contains the single sentence ‘True(T)’ (see Peacock (2011: 81–2), who calls T* a “meta-theory”). T and T* mutually entail one another (assuming ‘K’ is not a semantical predicate); they thus have the same ontological commitments on an entailment account. And this seems right. Surely, a philosopher cannot eliminate her commit