Informal answer:

What if some clever philosopher argues that enforced cultural norms (enforced moral standards) ought to be something else?

Philosophers have been arguing that enforced moral standards ought to be something else for as long as there have been philosophers. So it is doubtful that will stop.

What may not be logically possible though is to conclusively show that the function of enforced moral standards, the primary reason they exist in societies, is something else than what I have proposed. It appears to be empirically true that the universal function of enforced moral standards is “to increase the benefits of cooperation in groups by altruistic acts”.  I don’t see there is sufficient ‘room’ in reality to show the function of enforced moral standards, the primary reason they exists in societies, is anything else.

Perhaps it might be argued that the function of enforced moral standards is to increase all pro-social behavior, not just altruistic pro-social behavior. For example, self-interested cooperation in money based economies, as Adam Smith described many years ago, can have many pro-social results even when everyone is only pursuing their own self-interest. Adam Smith was right.

However, does it make sense for a society to waste resources on enforcing a norm that people are self-interestingly motivated to pursue anyway? Does it make sense to actively punish violators who do not pursue their self-interests in money economies? I don’t see that it does. Consistent with this line of thought, I am not aware of any enforced cultural norm that does not advocate behavior that is in some sense altruistic.

Perhaps, but what if a clever philosopher argued that “Yes, your universal function of morality may, in fact, be correct, but we will all agree that just because something ‘is’ does not mean that it ought to be. My new, very clever, argument shows that enforced cultural norms ought to be based on something different than social morality’s universal function”.

Fine, no logical problems yet. But then the clever philosopher must climb a high barrier, explaining a rational justification for accepting the burdens of his alternative morality. If he claims his morality entails an imperative ought, then he must identify what in physical reality binds people to conform to his morality regardless of their needs and preferences. He has to justify the reality of ‘magic’ oughts, which no one has ever conclusively done to date, and I expect never will – reality just doesn’t work that way.

Or, the clever philosopher might claim his alternative (as I claim for my functional definition of social morality) is a superior instrumental ought. That is, the philosopher might say “You ought to accept the burdens of this alternative social morality in order to achieve some overriding desire”. This is not a logical impossibility. But if the overriding desire is something like durable well-being (happiness) over a lifetime, or any other desire best fulfilled by cooperation in groups maintained by altruism, it does not seem likely..

Evolutionary Morality is almost certainly a better instrumental choice because, if true, it’s benefits were the forces that shaped human moral psychology and largely shaped our experience of durable well-being, a standard overriding goal of instrumental oughts.

That is, this function’s implied moral principle, “Altruistic acts that also increase the benefits of cooperation in groups are moral”, matches people’s needs and preferences like a key in a well-oiled lock.

Of course, some might say that even self-interested pro-social behaviors actually are part of the answer to the big question “How should I live?” and therefore part of morality. No problem, but self-interested pro-social behaviors are not, so far as I am aware, not advoated by enforced moral standards whose violators deserve punishment, which is the topic here.

Some readers may enjoy reading the pages “It is intrinsic to physical reality and universal”, “Explanatory power for myriad facts”, “Explanatory power for puzzles about morality”, and “Unity with the rest of science”. The explanatory power of Evolutionary Morality has answered questions about moral puzzles I have had all my life.

More formal answer:

There are two interlocked empirical claims that could be proved wrong:

1) “The primary reason that enforced cultural norms (enforced moral standards) exist is to increase the benefits of cooperation in groups by altruistic acts”
– Could be shown to be false by failing to meet  normal criteria for provisional truth in science such as: a) no contradiction with known facts,  b) superior explanatory power for known facts and puzzles about morality such as why enforced cultural norms are so superficially contradictory and sometimes bizarre , and c) unity with the rest of science (predominantly biological and cultural evolution and game theory)
– See “It is intrinsic to physical reality and universal”, “Explanatory power for myriad facts”, “Explanatory power for puzzles about morality”, and “Unity with the rest of science” to see how high the bar is set, in my mind very high, for any competing hypothesis about the function of social moralities in societies.

2) “Virtually all past and present enforced moral standards advocate altruistic acts that increase the benefits of cooperation in groups”
– Could be shown to be false by identifying counter-examples of past or present enforced cultural norms (norms whose violation commonly engenders the emotion indignation and idea that the violator deserves punishment).
– The phrase “virtually all” is used not because I have identified counter-examples, but because I have not been able to argue they could not exist in the chaos and diversity of human enforced cultural norms, in particular on a temporary basis.

The third claim is not necessarily dependent on claims 1) and 2). It could still be true, but less likely true, even if the empirical claims 1) and 2) are shown to be false.

3) “Altruistic acts that also increase the benefits of cooperation in groups are moral” is the moral principle, of all presently available alternatives, that, when implemented as the basis of enforced moral standards, will be the most effective at meeting common goals and desires of groups and individuals. That is, accepting, almost always, the burdens of this moral principle is the best instrumental choice for groups and individuals.
– This claim could be false if some other moral principle was proposed that somehow better met the needs and preferences of groups and individuals.
– If claims 1) and 2) are true, then claim 3) is supported because “the primary reason that social morality exists in societies” has been what has shaped our moral sense and emotions and largely what has shaped our experience of durable well-being, a common overriding desire for instrumental choices.
– That is, the primary reason that morality exists (social morality’s function) sums up the forces that designed our moral aspects and much of our experience of durable well-being. Therefore, this function defines a universal morality that fits us like a key in a well-oiled lock.

Assume for a moment that the above empirical claims 1) and 2) become generally accepted as true and at least some people conclude that Evolutionary Morality is the best basis for defining what norms to enforce in their groups and for what moral norms they, as individuals  ought to conform to.

There is no apparent logical prohibition against, sometime in the future, perhaps some other instrumental ought regarding some other moral principle, perhaps meeting some different overriding desire, will be found more attractive for adoption and practice.  Or perhaps some clever philosopher will convince everyone of the reality of some imperative ought.

If either of these events happens, Evolutionary Morality could become culturally irrelevant as a basis for enforced cultural norms. Based on the history of moral philosophy in the last few thousand years, I don’t see either of these two hypothetical events as being likely.

The picture of partially chewed on leaves represents one way I think of Evolutionary Morality. It is not perfect, but it still has great beauty in its simplicity and, in its inner workings, it is an indestructible force in the universe in the same way biology is.