system
Given the following post, respond as if you're commenting on Reddit:
human
How plausible is utilitarianism from a meta-ethical perspective?
gpt
On the face of it, metaethics has nothing positive or negative to say about utilitarianism, since utilitarianism is not a metaethical theory, but a first-order theory of normative ethics. You could have a dozen utilitarians who entirely agree on first-order issues, but who hold completely different views on metaethical issues.

Hell, even an error-theorist could be a utilitarian. Mackie's first-order views were at least in the neighborhood of utilitarianism.