Here is my reconstruction of G. E. Moore's Open Question Argument.
- Suppose that “A is good” means the same as “A is what we desire to desire."
- Then, “Is what we desire to desire good?” means the same as “Is what we desire to desire what we desire to desire?” 
- But the first question is significant – there would be a point in asking the question – whereas the second question is trivial – there would be no point in asking the question.
- So the two questions do not mean the same.
- So “A is good” does not mean “A is something we desire to desire.”
Ultimately, Moore concludes that we cannot give any conceptual analysis of the term 'good' because it is simple and only complex concepts can be given an analysis.
Question: Is Moore's argument sound? Why or why not?
 (2) follows from (1) because we are substituting 'desire to desire' for 'good' and this is supposed to have the same meaning by hypothesis according to (1).