Maximizing benefit to society is the ultimate goal of all morality
"Maximizing benefit to society is the ultimate goal of all morality" is a claim about the nature of morality.
Furthermore, if we adopt ultimate moral values which conflict with each other (e.g. Moral System A says "gostaks must never distim doshes" and Moral System B says "gostaks must always distim doshes"), then there is no way to resolve the conflict short of a contest of strength, which would be harmful.
If there is no larger reason to adopt a moral system, and adopting one without such reason can be harmful, then it seems also inescapable that groundless moral systems are themselves immoral (in the larger ethical sense).
Part of the problem may be in how people define "society"; if you think of "the church" or "the government" or "my country" as being all of society (or all that matters), then you may think you do not need to defend statements such as "the good of the church is all that matters." or "My country, right or wrong."
However, each of these entities exists within (and would be substantially reduced without) a larger social context which currently extends to all of humanity all over the planet. If we ever colonize space or encounter sentient aliens, then that social context will need to expand further if we are to avoid a strength contest.
- This statement needs to be subjected to structured debate.
- For now, though, it seems to be inescapably true.