I mean the former: like, whatever “utility” is is not a simple thing to define in terms of things we have a handle on (“pleasurable mental states” does not count as a simple definition), and even if you allow yourself access to standard language about mental states I don’t think it’s so easy (e.g. there are a bunch of different sorts of mental states that might fall under the broad umbrella of “pleasure”).
I do agree that “not for the sake of happiness alone” argues against utilitarianism.
I mean the former: like, whatever “utility” is is not a simple thing to define in terms of things we have a handle on (“pleasurable mental states” does not count as a simple definition), and even if you allow yourself access to standard language about mental states I don’t think it’s so easy (e.g. there are a bunch of different sorts of mental states that might fall under the broad umbrella of “pleasure”).
I do agree that “not for the sake of happiness alone” argues against utilitarianism.