 Reductive normative naturalism claims that naturalistic constitutive explanations of normativity and of the normative properties and concepts are available, at least in principle. We began  section 3  with the question whether normativity can be given a naturalistic constitutive explanation. Reductive normative naturalism offers an affirmative answer. Some naturalists might merely have the aspirational view that although an adequate reduction is not yet available, we should expect there to be one in the offing, since the normative states of affairs and properties are natural. But the most interesting forms of reductive normative naturalism offer accounts of the nature of normativity, or at least sketches of such. Theories of this kind propose, for each normative explanandum and for the property of normativity itself, a natural property as its explanans.