 It is also possible that the most reasonable account of conceptual content will leave many concepts with significantly indistinct borders. There may simply be no fact of the matter about whether moral discourse is committed to the existence of non-instrumental reasons (for example). Thinking along these lines, David Lewis makes use of the distinction between speaking strictly and speaking loosely: “Strictly speaking, Mackie is right: genuine values would have to meet an impossible condition, so it is an error to think there are any. Loosely speaking, the name may go to a claimant that deserves it imperfectly … What to make of the situation is mainly a matter of temperament” (Lewis [1989] 2000: 93). Lewis’s own temperament leads him to seek to vindicate value discourse, and he thinks that this can be done by supporting a dispositional theory of value (of a kind to be discussed in the next section). But since there is no logical or methodological requirement that we should prefer speaking loosely over speaking strictly, or vice versa, then this would leave the dispute between moral error theorists and success theorists a fundamentally undecidable matter—there may simply be no fact of the matter about who is correct. (See Joyce 2012.)