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
