[The Main Claim] The role of non-natural properties is not to be the reasons to which we should respond, rather to mark which natural properties serve as such reasons.
In order to defend this non-naturalist picture of normativity, Chappell discusses two arguments against non-naturalism: the argument from unintelligible concern and the argument from moral idlers.
[The Argument from Unintelligible Concern]
Commitment to natural features may be intelligible, but commitment to non-natural properties are not intelligible. Our commitment to natural features is intelligible while our commitment to non-natural properties is not.
Chappell's response: we should make a distinction between the de re reading and the de dicto reading of the function of non-natural properties. Non-naturalists are not committed to the idea that we are motivated by the thought of non-natural properties on the de dicto reading.
[The Argument from Moral Idlers]
In order to be normatively significant, non-natural properties need to feature in correct justification.
Chappell's response: non-natural properties have a different role in accounting normativitiy, such as a truth maker for the claim that the natural property of killing many and saving none is to be avoided. So, even if they are not part of justificaiton, still they have an important role.
Chappell thinks that Bedke's objection is somewhat different from Jackson's original one.
Bedke's Claim: the wrong making features of the act in question is its natural features, such as the causing of pain. Those natural features have normative significance.
Chappell: the non-naturalist simply claims that there are no further answers concerning the question 'what does the wrongness of the act consist in?'. The non-naturalist says what makes the act wrong is just the non-natural wrongness as such, and this is a brute fact.
Chappell's distinction between 'the constitutive sense' and the normative sense'. The former is the sense that the wrongness of the act consist in non-natural properties while the latter is the sense that what makes the act wrong is its natural features.