Knowing Enough to Disagree: A New Response to the Moral Twin Earth Argument

Abstract

Abstract At the beginning of the twentieth century, G. E. Moore’s open question argument convinced many philosophers that moral statements were not equivalent to statements made using non-moral or descriptive terms. For any non-moral description of an action or object it seemed that competent speakers could without confusion doubt that the action or object was appropriately characterized using moral terms such as ‘good’ or ‘right’. The question of whether the action or object so described was good or right was always open, even to competent speakers. In the absence of any systematic theory to explain the possibility of synthetic as opposed to analytic identities, many were convinced this demonstrated that moral properties could not be identified with any natural (or supernatural) properties. Thus Moore and others concluded that moral properties such as goodness were irreducible sui generis properties, not identical to natural properties (Moore, 1903: 15). Noncognitivists used the same argument to support the idea that moral judgments have an expressive function rather than a representational function. Their explanation for the failure of competent speakers to recognize the equivalence of moral predicates with other predicates was that these terms, unlike other predicates, did not serve to represent properties at all (Ogden and Richards, 1923: 125).