Strength and Stability

In this paper, I present two presumed alternative definitions of metavalidity for metainferences: Local and Global. I defend the latter, first, by arguing that it is not too weak with respect to metainference-cases, and that local metavalidity is in fact too strong with respect to types. Second, I show that although regarding metainference-schemas Local metavalidity is always stable, Global metavalidity is also stable when the language satisfies reasonable expressibility criteria (and that in fact, both concepts collapse in those cases).