Minimum Conception of Morality

After reading Chapter 1 (pgs. 1-13); Chapter 2 (pgs. 14-29) of the text book James Rachels – The Elements of Moral Philosophy (7th edition edited by Stuart Rachels) (New York: McGraw-Hill: 2012) and the attached material (A Refutation of Morals by J.L. Mackie) I need to write about the following:

Describe what Rachels calls “the minimum conception of morality.” Compare it with J.L. Mackie’s skepticism about morality (which you might also have to explain and illustrate with examples). Do they completely disagree or is there some room for overlap? If they disagree, which do you side with? Explain why?