 It is a “significant” or non-analytic proposition because a competent speaker can believe that X is the act that will produce the best consequences without believing that she ought to do it. If the two propositions “X is the act available to me that will produce the best consequences” and “I ought to do X” were really synonymous, then a competent speaker could not believe the one whilst remaining in doubt about the other. Since this is perfectly possible (as is shown by the fact that “Ought I to do what will have the best results?” is an obstinately open question for competent speakers of English) the two claims are not synonymous. (W.D. Ross developed a similar line of argument in The Right and the Good (1930) but it was Russell who convinced Moore that he was wrong. See Moore 1942: 558).