Conservativeness and Metaontology

This paper investigates the role conservativeness plays in metaontologies. Hartry Field famously uses conservativeness to argue that mathematical theories are not ontologically committing. However, deflationary metaontologies tend to invoke conservativeness to opposite ends: they argue that the addition of certain entities is legitimate. I argue that Field's use of conservativeness is trouble-free, whereas that of the deflationists is not. To do so, I consider Stephen Schiffer's pleonastic account as a case study.