Are there "general universal norms" that explain divergence in particular cases such as property/taxation is theft, ones that are held by all people? Is that the same as asking whether in every moral disagreement there is at least one shared value
anti-relativists counter-argue that the observed diversity and lack of convergence in local norms can in fact be explained by some very general universal norms, which combine with the different circumstances (or false empirical beliefs) of the different groups to entail different particular norms. The objectivist thereby can accommodate diversity and lack of agreement at this higher level of generalization (see Philippa Foot (1982) for this type of argument).
https://plato.stanford.edu/entries/relativism/
I understand what someone means when they say taxation is theft, and that they mean it, but unless we see ethics as wish fulfillment, I cannot easily explain the divergence, reduce it to shared values.
Perhaps the joys of extreme wealth and the value of self interest are all that matter in some beliefs, and that suffices to explain differences. So does anti-relativism amount to the claim that there is always in every divergence at least one shared value, even if it is just comes down to the limit case of getting what you want?