 Third, some realists are prepared to claim more ambitiously that we can give a conceptual analysis of rightness in base terms (e.g. Jackson 1998, Ch. 5). Such philosophers can thereby deny (2), cutting the argument off at the knees. (Dreier 1992, 17–18 suggests that Blackburn’s argument simply begs the question against this sort of reductive realist.) Such realists take on the burden of rejecting the most famous argument in metaethics: G. E. Moore’s “open question argument” (1903, Ch. 1). However, it is a hotly contested question what—if any—probative value this argument has (for discussion, see section 2 of the entry on  moral non-naturalism).