Abstract

Moral error theorists often claim to be strongly anti‑metaphysical in their moral scepticism and atheistic naturalists. This paper argues that pre‑ cisely this becomes a problem for them, when their metaethical and ontologi‑ cal commitments clash. I first outline how the known arguments against error theory face a problematic, yet rarely considered trade‑off : either they are very strong, then they are also very demanding in their assumptions or they are less demanding in their assumptions but rather weak in their conclusions. In re‑ sponse to this challenge I then develop a new argument against error theory that exploits an overlooked inconsistency in the error theorists’ standard line of argumentation. I conclude that the implications of this inconsistency are less of a problem for fictionalist error theorists, but will render any eliminativism based on error theory circular.