Tanaka, KojiGirard, Patrick2025-11-052025-11-050003-2638https://hdl.handle.net/1885/733793857There was a time when ‘logic’ just meant classical logic. The climate is slowly changing, and non-classical logic cannot be dismissed off-hand. However, a metatheory used to study the properties of non-classical logic is often classical. In this paper, we will argue that this practice of relying on classical metatheories is problematic. In particular, we will show that it is a bad practice because the metatheory that is used to study a non-classical logic often rules out the very logic it is designed to study.Koji Tanaka is supported by an Australian Research Council Future Fellowship [FT160100360].application/pdfen-AU© 2023 The Author(s)2023-04-0110.1093/analys/anac093