You don't understand that "common good" is impossible to define. This is one of the most basic discoveries of utilitarian ethical theories. It is sensible to ask what someone means if they use the term "common good" within the context of a proposal, but there is no general meaning of common good. There absolutely can't be.
"You don't understand that "common good" is impossible to define"
Maybe I do understand that. I'm not "sea-lioning" you at all. I'm just responding to a derisive and dismissive remark you made to a (IMOP) valid point. I don't necessarily believe in the validity of "discoveries" of utilitarian ethics. But I do believe "good" has, as you say, no general meaning. Which is why it is an interesting question.
You don't understand that "common good" is impossible to define. This is one of the most basic discoveries of utilitarian ethical theories. It is sensible to ask what someone means if they use the term "common good" within the context of a proposal, but there is no general meaning of common good. There absolutely can't be.