More on Framing the Internalism/Externalism Debate

In my post I forgot to link to the post on my blog which discusses theories of evidence. Here it is.

One clarification in my point about PF and EP’s. In the discussion on evidentialism I focused on EJ rather than ES because I don’t particularly find supervenience a helpful notion. I don’t think I made clear that there’s probably no way to get strong supervenience out of PF, since, unlike EP’s DP’s (design plans) will vary not only from world to world, but from species to species within worlds.

It’s not clear to me that at some level of generality you won’t get supervenience of justification on broad mental types, but at that level of generality it might get unenlightening: any two individuals in any world who are alike in that their beliefs are supported by the experiences their design plans say ought to support those beliefs are alike in respects of justification.

However, it’s *also* not clear to me that this level of generality isn’t *more* informative in some respects. It’s a tough issue. So that’s what I’m not saying and what I’m not confident of. Here’s what I am saying and what I’m pretty confident of.

SUBSTANCE: There is no “relevant”/“substantive” violation of evidentialism in PF theory since anything that’s “external” about PF is, I think, true mutatis mutandis about EP’s.

True, DP’s will, on one theory of EP’s, vary more than DP’s.

FUNCTION FIXITY: Holding DP’s fixed the evidence is the only thing that determines justificatory status.

Compare:

PRINCIPLE FIXITY: Holding EP’s fixed the evidence is the only thing that determines justificatory status.

P-FIXITY might seem odd since you can’t help but hold the necessary fixed. But this is *precisely* where I think I can support SUBSTANCE. Here’s a *really* internalist view: Bayesiansim. On personalist bayesianism (*not* a redundancy contrary to many) the EP’s are a persons conditional personal probabilities (how much *they think* one thing makes another probable). So here not only do EP’s vary from world to world and species to species but from *person to person*!

So how do the subjectivist internalist and the objectivist internalist differ? Just in respect of how fixed EP’s are. Now when evaluated along one dimention—the mental—both count as mentalist internalists because subjectivist EP’s are mental states, so supervenience holds BUT FOR A TOTALLY DIFFERENT REASON. This should tell us that supervenience isn’t doing much relevant explanatory work. what really matters in a theory is WHAT EXPLAINS FIXATION.

A really natural definition of internalism would have been (and John Turri seems to think it was):

MENTALISM*: Theory T is an internalist theory of epistemic justification iff THE TOTAL STORY ABOUT JUSTIFICATION makes reference only to mental states.

Notice that Rich and Earl’s view is not a species of MENTALISM* due to the requirement of necessary epistemic principles. Now *surely* the “real” debate is not about whether mentalism or MENTALISM* is the best. It seems to me the debate is about what determines fixity. After that—as is platitudinous—it’s all a matter of evidence.

Let’s call the fixors the “evidential superstructure” of a theory of justification (the theory of evidence would be the “meat” of the view (I’m not trying to connote anything but a form vs. matter contrast). Personalist Bayesians think mental states themselves determine the evidential superstructure, Chisholmians think necessary truths form the evidential superstructure, proper functionalists think design plans form the evidential superstructure.

This, it seems to me, is the most helpful way to frame the debate.