(i) Identify and explain the way in which Common Cultural Relativism is incoherent

     Common Cultural Relativism (CCR) is incoherent in three different ways.  First, thesis 6 is not compatible with thesis 4.  Thesis 4 says denies that there are any "universal truths" in ethics.  But thesis 6 seems to assert a universal moral truth that applies to everyone -- it says that all of us morally should do be tolerant toward the practices of other cultures.
     Second, thesis 5 is not compatible with thesis 4.  Again, thesis 4 says there a no universal truths in ethics, but thesis 5 implies that that there is.  For thesis 5 says that it is a universal truth that everyone is morally required to do what his society's moral code requires him to do.
     The third conflict among the theses of CCR occurs between 5 and 6.  Thesis 5 says that everyone should be more tolerant.  Thesis 4 says that we should do whatever our society's moral code says we should do.  But what if our society's moral code requires us to be intolerant toward the practices of other cultures?  In such a case, thesis 5 would imply that tolerance is wrong, and thesis 6 would imply that tolerance is not wrong.  This is a contradiction.

(ii) Suggest how CCR can be modified to be made coherent.

     The first thing that should be done to make CCR coherent is the complete elimination of thesis 6.  There is no way one can hold both the claim that morality is determined by whatever society says and the claim that everyone should be tolerant.  Since the former view is more central to the main idea behind cultural relativism, thesis 6 should be dropped.
     Thesis 4 also needs to be dropped.  Thesis 5 implies that there is a universal truth in ethics (namely, an act is right if the moral code says it is).  Since 4 and 5 are in deep conflict, and since 4 is more central to the main idea behind relativism, thesis 4 should be dropped.
     This new version of CCR, which consists on theses 1, 2, 3, and 5, is at least consistent.

(iii) Discuss your reaction to this new view. Do you find plausible the idea that morality is based on what society thinks? Why or why not?

     Even though this new view is an improvement over the original (since it is not incoherent), I still don't find it very plausible.  I think it is possible for a society to be mistaken about morality.  For example, some societies think slavery is morally acceptable.  But slavery is an absolute outrage, no matter where and when it occurs, and no matter what the moral code of the society in which it occurs.  Slaves lead miserable lives.  They are robbed of their freedom; they don't enjoy the benefits of an education; they are usually separated from their families; and they are forced do back breaking, demeaning work all the days of their lives.  Any moral theory that says that is morally permissible to treat someone like this is not to be taken seriously.