Bart Streumer believes that the following principle is true of all normative judgements:
(A) When two people make conflicting normative judgements, at most one of them is correct. Streumer argues that noncognitivists are unable to explain why (A) is true, or our acceptance of it. I argue that his arguments are inconclusive. I also argue that our acceptance of (A) is limited in the case of instrumental and epistemic normative judgements, and that the extent to which we do accept (A) for such judgements can be explained by an assumption of shared standards of correctness. Finally, I argue that reductivists can appeal to the same ideas to defend their view that instrumental and epistemic normative judgements describe non-normative relations.