These issues may seem to be strictly insoluble, but they “mostly take rise from a regular confusion between ontological and epistemological issues which cannot but lead to some skeptical outcome.”

Response-dependence (RD) has its roots in Locke’s discussion of secondary qualities (like color, taste and odor) as distinguished from primary qualities (objective attributes like shape and size). The secondary qualities depend on a respondent, and some RD theorists expand this to other areas of debate as an alternative to hard-line realism on the one hand, and hard-line anti-realism on the other.

“The chief purpose is to specify these various provisos with maximum precision and thereby establish a class of perceptions and judgments which, although they lack objective (observer-independent) truth conditions, can nonetheless be treated as subject to normative standards of veridical warrant. By doing so, its advocates believe, one can make a strong start in heading off those skeptical arguments that have often traded—at least since Locke—on the subjectivity of color-perception and other such secondary qualities.” It also provides a way to distinguish between areas where this approach is adequate, and areas where, “according to the realist, our statements must be taken as possessing an objective truth-value quite aside from the vagaries of human perceptual response or the scope and limits of epistemic warrant.”

RD theorists take issue with Kripke’s “skeptical solution” to Wittgenstein’s rule-following paradox. Kripke accepts Wittgenstein’s anti-foundationalist claim that standards of correctness for any rule-following depend on communal warrant. When a person produces an outcome different than the outcome we would produce when following accepted rules, s/he either hasn’t understood the rules, or s/he is following different rules. However, Kripke argues that if s/he produces the outcome that we would produce, that doesn’t guarantee s/he has understood accepted rules—s/he could have arrived at the same outcome via different rules. He says this conclusion follows from “the twin Wittgenstein considerations” that 1) the meaning given to the signs we use to communicate the rules—that meaning is not a “fact” and 2) every rule has a rule for its correct application, creating an infinite regress of rules, and no objective bedrock. So, Kripke says the only possible ‘solution’ is to take “a lesson from Wittgenstein in viewing our communal practices, procedures or shared ‘forms of life’ as the furthest we can get by way of justification for maintaining” our rules against the other’s “idea of what counts as properly or correctly following a rule.”

Crispin Wright’s “chief motive for adopting an RD approach is the hope of finding some alternative to ‘Kripkensteinian’ skepticism that would register the force of such arguments while yet making room for a realist-compatible conception of those areas of discourse where, intuitively, truth cannot be just a matter of conformity with accepted practices and norms.” BUT—Wright still has issues with the objectivist idea of arithmetical rules being true before we’ve grasped them (like Fermat’s Last Theorem before Andrew Wiles’ proof)—the same idea of which Alex Miller’s “humanized Platonism” stops short.

This is because RD theory’s emphasis is on what comes after “if and only if,” to “privilege issues of perceptual response or judgements arrived under normal (suitably provisoed) epistemic conditions over issues of objective truth or those that might more aptly be addressed by the methods of the physical sciences.”