I promise to avoid bad puns in future titles.
David Copp advances a “society-centered” theory (SCT) of the justification of moral standards in Morality, Normativity, and Society. It’s a standard-based theory. “Standard” is used in this context to name a rule or imperative, for example, “Do not torture innocent children to death.” Imperatives have no truth conditions. But this does not prevent a moral claim from having truth conditions. A claim endorsing the standard, like “It is wrong to torture innocent children to death” expresses a proposition about the standard. It asserts that a standard that calls upon people to avoid torturing innocent children to death is appropriately justified. This proposition is true only if there is a standard that calls upon people to avoid this behavior, and this standard is appropriately justified.
There are, of course, many different accounts of the conditions under which a moral standard is appropriately justified. The correct account will be the one that gets things right about what actually justifies the standard; it will determine the truth conditions of moral propositions. Copp’s moral theory is society-centered. This means that the theory justifies moral standards in terms of the needs of a society. By the lights of SCT, a moral standard is justified upon the condition that the society, given its needs, would be rationally required to select the standard as part of its moral system. By the lights of SCT, a moral proposition endorsing the standard, asserting in effect that the standard is justified, is true if and only if it would be rationally required for the society to select the standard given its needs. The proposition really is true if SCT provides the correct account of the conditions under which a moral standard is appropriately justified.