If we are simply to understand the link between observation and science, we are well advised to use any available information, including that provided by the very science whose link with observation we are seeking to understand.' A naturalist need not be afraid of circularity.
For if the practicality requirement on moral judgement is correct then the non-naturalist needs to provide some account of why an agent's recognition that one of the actions available to her has the non-natural property of rightness is such that her recognition of this fact rationally requires that she be motivated to perform the action.
Second, how far do methodological naturalists need to allow that mathematics, morality and modality constitute exceptions to their position in the first place?
Mackie's argument seems to "load up" the concept of a moral property with a lot of baggage that the non-naturalist need not accept.
Any kind of moral naturalist realist needs to reject Moore's open question argument.
When Lear invents the Pobble Who Has No Toes, he is mocking the naturalist's need to give a name to each new thing.
It is not, of course, entomologists, or even weekend naturalists, who need convincing about the richness of the forest floor.
However, the non-naturalist will need a separate argument against those naturalists who hold that moral properties natural but irreducible.
Although he discussed his ideas with several naturalists, he needed time for extensive research and his geological work had priority.
Some M-naturalists want "continuity with" only the hard or physical sciences (Hard M-naturalists); others seek "continuity with" any successful science, natural or social (Soft M-naturalists).
The contrast between the different perspectives on properties brought to light in §4 gives us some reason to think that accounts in different fields (e.g., semantics and natural ontology) may call for entities with different identity conditions; for example, semantics requires very finely individuated properties, whereas naturalist ontology may need more coarsely individuated ones.
