Morality is a mechanism that helps with following some rules within a society without spending excess resources on enforcing them. It evolved in small groups (i

Morality is a mechanism that helps with following some rules within a society without spending excess resources on enforcing them. It evolved in small groups (in comparison to the size of societies today). If you accept this view on what morality is then it's pretty obvious there ought be some universal rules as human groups have a lot in common and some rules universally help with survival of a group. "Don't kill your peers" is one example. "Don't take their property without their consent or some process" is another although it can only arise in groups advanced enough to come up with the concept of property. Then there is a whole set of rules related to sex and reproduction which are again pretty universally needed for the group survival but can be established in various way - there more than one solution giving a chance for group's survival unlike in "don't kill your peers" case. I am yet to meet a fundamental moral relativist who claims we can adopt any rules we please but a position that there are many set of rules that arised to help with the purpose of group's survival is both common and imo obviously correct. There is in fact an underlying mechanism for moral rules (group survival) which those rules stem from in one way or another. There might be better or worse set of rules and they might be different depending on environment a given group exists in. "Don't kill your peers" is going to be there but "Don't kill the weakest members of the group so the resources can be saved" not necessarily so. It seems to me that Chomsky is arguing against a very narrow and strict definition of moral relativism here or I am not getting his point.