 The error-theories proposed by Mackie and Field are non-eliminativist error-theories, and should be contrasted with the kind of eliminativist error-theory proposed by e.g. Paul Churchland concerning folk-psychological propositional attitudes (see Churchland 1981). Churchland argues that our everyday talk of propositional attitudes such as beliefs, desires and intentions should eventually be abandoned given developments in neuroscience. Mackie and Field make no analogous claims concerning morality and arithmetic: no claim, that is, to the effect that they will one day be in principle replaceable by philosophically hygienic counterparts. For some discussion of the contrast between eliminativist and non-eliminativist error theories, see Miller (2015). 