  There are of course many ways to resist these arguments. Perhaps moral expressions are analytically equivalent to naturalistic expressions, but these analyticities are themselves not obvious even to competent speakers (Lewis 1989, 129). This may be because no analyticities are obvious, or it may be because moral analyses in particular are especially complex. One moral that could be drawn from the history of Twentieth Century analytic philosophy is that if there are any analyticities, competent speakers can question them. This is the paradox of analysis. If any definition can be questioned by a competent speaker, and we think there are at least some definitions sufficient to underwrite analytic truths, then the mere fact that a speaker can doubt a candidate analysis may not tell against that analysis. An equivalence could be analytic because competent speakers tacitly respect it, for the most part acting as if the equivalence is true (Lewis 1989, 130). It has been suggested that moral concepts are role concepts analogous to the concepts of various mental states as conceived by functionalists. The idea is that commonsense morality embodies a theory of morality which specifies the ways in which various moral properties (rightness, wrongness, goodness, badness, fairness, etc.) are related to each other and to other properties. When we put all of the claims of the commonsense theory together it specifies a role that each property must play in terms of the other properties it relates to.  The role concept so-specified for each term might then be the concept of the referent of that term (Jackson and Pettit 1995). If so we should expect such concepts to be quite complex. And their complexity might make it hard to recognize the adequacy of any analysis, even for speakers who tacitly respect the equivalence so defined.