 A second objection to the sufficiency of the quantifier account relates to the interpretation of the quantifiers of first-order logic. If the quantifiers are interpreted substitutionally, instead of objectually, the criterion may overgenerate. According to the objectual interpretation (due to Tarski), an existentially quantified sentence ‘∃x φ(x)’ is true if and only if the open formula ‘φ(x)’ is satisfied by some object in the domain. According to the substitutional interpretation, ‘∃x φ(x)’ is true if and only if ‘φ(t)’ is true, for some singular term ‘t’ of the language. When the quantifiers are given a substitutional interpretation, Quine's criterion will overgenerate if the language has empty singular terms. For example, a theory that contains (a symbolic translation of) the sentence ‘Sherlock Holmes is a fictional detective’ would be ontologically committed to fictional objects, and that seems wrong.