  Consider someone who held not merely that pleasure was something good but (as a definition would have it) that pleasure was goodness—that they were one and the same property. According to that person, in claiming that something is pleasant one is claiming that it is good, and vice versa. In that case, though, it would not make sense for people to acknowledge that something is pleasant and then wonder, nonetheless, whether it was good. That would be like acknowledging that something is a triangle and then wondering, nonetheless, whether it has three sides. Yet, Moore maintained, the two cases are not alike. A person who wonders whether a triangle has three sides shows he does not understand what it is to be a triangle. His competence with the terms in question is revealed to be inadequate. In contrast, Moore observed, for any natural property whatsoever it was always an open question whether things that had that natural property were good.  A person who raised that question did not thereby reveal himself not to be competent with the terms in question. What this shows, Moore argued, was that moral terms did not refer to natural properties and so a proper account of moral claims would have to recognize that they purport to report non-natural facts.