The mathematical fictionalist way out is to avoid moving to the metalanguage in order to express the conservativeness of mathematics. The idea is to state, in the object-language, the claim that a given mathematical theory is conservative by introducing a primitive notion of logical consistency: ◊A. Thus, if B is any sentence, B* is the result of restricting B to non-mathematical entities, and M1, …, Mn are the axioms of a mathematical theory M, the conservativeness of M can be expressed by the following schema (Field 1989, p. 120):