 Streumer defends  (4),  the last step to the error theoretic conclusion, the claim that normative properties are not natural ones. Arguments for this claim are, however, pivotal to many arguments about the nature of normativity, and not merely to an argument for the error theory. They are pivotal in arguments in favor of non-naturalism, the view that normative properties exist but are not natural properties. And they are pivotal in arguments in favor of non-cognitivist/expressivist theories, theories that hold that normative predicates do not ascribe or refer to normative properties at all, but have a very different semantic role. So, since arguments against normative naturalism are of very wide importance, we will consider them separately.