 Is this a good argument? Not by itself, no. For it is not clear that theses a) and b) represent genuine facts. And even if a) and b) are true and do represent genuine facts, is c) the best explanation? Perhaps there is a property of goodness but it happens to be a property that it is difficult to discern. Some people are just better at seeing what is good or bad than others. As Russell himself put it in 1909 “the difficulty of discovering the truth does not prove that there is no truth to be discovered” (Philosophical Essays: 20/Papers 6: 222).