Introspective and Reflective Distinguishability

Mooreans, including neo-Mooreans, think that we know lots of ordinary stuff, and that we also—maybe on this basis—know the denials of extraordinary skeptical scenarios. Duncan Pritchard defends a particular disjunctivist brand of neo-Mooreanism, according to which, in cases of successful perception, one has reflective access to factive reasons of the form I see that p, and perceptual knowledge based on such reasons. So for instance, when one looks at red wall under ordinary circumstances:

• One sees that the wall is red.
• One has reflective access to the fact that one sees that the wall is red.
• One knows that the wall is red on the basis of the fact that one sees that the wall is red.

Since Duncan also accepts a closure principle on knowledge, he accepts:

• One knows that the wall isn't a white wall illuminated by red light.

Like all forms of Mooreanism, Duncan's view is in tension with certain skeptical intuitions. For example, it is in tension with this intuition:

(S) One can't tell by introspection that one is faced with a red wall rather than a white wall with red light.

As Duncan puts it,

If, in the non-deceived case, one has reflective access to the relevant factive reason as epistemological disjunctivism maintains, then why doesn't it follow that one can introspectively distinguish between the non-deceived and deceived cases after all, contrary to intuition? ... In short, the problem is that it is difficult to see how epistemological disjunctivism can square its claim that the reflectively accessible reasons in support of one's perceptual knowledge can nonetheless be factive with the undeniable truth that there can be pairs of cases like that just described [ordinary perceptual cases and corresponding deceptions] which are introspectively indistinguishable. (21)

(Duncan defines 'introspective indistinguishability' as the inability to know by introspection alone that the cases are distinct. (p. 53))

If I wanted to be a neo-Moorean of broadly Duncan's style (something I might well want to do), I'd just deny S, along with the many other skeptical intuitions that come out false on this view. But Duncan doesn't want to go that way; as this passage indicates, he considers S and claims like it to be 'undeniable truths'. (On p. 92 he even says that disjunctivists in particular are "unavoidably committed to denying that agents can introspectively distinguish" between the relevant cases.) I confess I don't see why it's so important to hold on to this particular skeptical intuition while happily rejecting others, such as the intuition that an ordinary person at the zoo doesn't know that she isn't looking at a cleverly disguised mule.

How does Duncan go about resolving the tension between his disjunctivism and S? By leaning on the 'by introspection' qualifier. He does think that, if one in the good case, one can reason thus, resulting in knowledge of the conclusion: "I have factive reason R. Only in the good case would I have factive reason R. Therefore, I'm in the good case." But, he says, this is consistent with intuitions like S, which are about introspective abilities. And while one may be able to tell by introspection what reasons one has, one cannot tell by introspection that factive reasons obtain only in the good cases. This is something one can come to know by a priori reflection, but not by introspection. (And maybe the same goes for the epistemic standing of the inference from the two premises to the conclusion.)

This is ultimately a much milder concession to skeptical intuitions than at first it appeared. Although he preserves the letter of his interpretation of the claim that we can't introspectively distinguish the good cases from the bad cases, he does so by pointing out that "introspectively" is a stronger qualifier than one might have realised. He does think (p. 95) that one can reflectively distinguish between good and bad cases, where reflective distinguishability is the ability to know distinct base on a combination of introspection and a priori reasoning.

So two thoughts. First the smaller one: is it really right to exclude a priori reasoning from the considerations that establish 'introspective distinguishability'? It's very hard for me to even make sense of just what that constraint is. (In The Rules of Thought, Ben and I argue that we can't divorce any kind of thought from a priori reasoning.) Consider these two cases: (1) I am presented in ordinary circumstances with a blue ball. (2) I am presented in ordinary circumstances with a black ball. Given the way my perceptual faculties work, we should consider these cases to be distinguishable in the relevant sense if any are. But is it clear that I can know them to be distinct without using a priori reasoning? It's not like the proposition that they're distinct is made available to me directly via introspection. Instead, I have introspective access to how one case looks, and to how another case looks, and I observe that they're different. From this I infer, using something like Leibniz's law, that they're distinct.

Second, supposing Duncan is right about introspective distinguishability: maybe this just shows that the worry wasn't properly articulated in the first place. I submit that someone motivated by the kinds of skeptical pressures that would drive someone to say that you can't tell good cases and bad cases apart by introspection, isn't going to feel better if you allow a priori reasoning along with introspection. The key skeptical intuition in the first place was just that it shouldn't be that easy to tell the good cases and the bad cases apart. And there's no getting around it: that's just an intuition that disjunctivists need to deny. Once we come to appreciate this fact, I'm not sure how important it is to conform to the letter of certain idiosyncratic statements of the intuition.

Pritchard on pragmatics of knowledge ascriptions

I'm working on a review of Duncan Pritchard's book Epistemological Disjunctivism. I'll probably try out a few ideas here over the next couple of months. I want to start out by focusing on something from near the end of the book—§8 of Part III. Here, Duncan is trying to deal with what he considers to be a challenge to the particular form of neo-Moorean disjunctivist response to the skeptical paradox he's been developing. The salient element of the view is that, contrary to skeptical intuitions, one does typically know that e.g. one is related in the normal way to the world, rather than being a brain in a vat. This, even though one lacks the ability to discriminate perceptually between being related in the normal way to the world and being a brain in a vat.

The challenge Duncan considers in this section is that Moorean assertions like "I know I'm not a brain in a vat" seem conversationally inappropriate. As he puts it earlier in the book,

[T]here appears to be something conversationally very odd about asserting that one knows the denial of a specific radical sceptical hypothesis. That is, even if one is willing to grant with the neo-Moorean that one can indeed know that one is not, say, a BIV, it still needs to be explained why any explicit claim to know that one is not a BIV (i.e., 'I know that I am not a BIV') sounds so conversationally inappropriate. Call this the conversational impropriety objection. (115)

The answer Duncan gives to this challenge in §8 ("Knowing and Saying That One Knows") is that the Moorean claims in question, in the contexts under consideration, generate false conversational implicatures to the effect that one has the relevant discriminatory abilities:

[I]n entering an explicit knowledge claim in response to a challenge involving a specific error-possibility one is not only representing oneself as having stronger reflective accessible grounds in support of that assertion than would (normally) be required in order to simply assert the target proposition, but also usually representing oneself as being in possession of reflectively accessible grounds which speak specifically to the error-possibility raised. (142)

I tend to be suspicious of pragmatic explanations for infelicity that don't come along with systematic explanations. Grice tells nice stories about how his maxims predict particular implicatures, given various contents asserted. What is Duncan's explanation for why first-person knowledge assertions implicate that one has the perceptual capacity to discriminate the state of affairs claimed to be known from alternatives that have been mentioned? Let's take an example, adapted from one of Duncan's (p. 146 -- one of his "unmotivated specific challenge" cases):

• Zula: [looking at some zebras in the zoo] There are some zebras over there.
• Asshole: They look like zebras. But who knows? Maybe they're cleverly disguised mules.
• Zula: I know that they're zebras.

Duncan's view is that Zula last utterance is true but unassertable—unassertable because it implicates falsely that Zula can discriminate perceptually between zebras and cleverly disguised mules. But why does it implicate that, if it doesn't entail it? I can't see how any of Grice's maxim's would generate the implicature in this case. Without some kind of story about where the implicature comes from, the suggestion that any impropriety comes down to pragmatics looks suspiciously ad hoc.

Notice also that certain predictions of the pragmatic explanation do not seem to be borne out. Since Duncan's story depends essentially on the implicatures involved in Zula's assertion, it does not extend to knowledge attributions that Zula doesn't assert. For example, it does not extend to Zula's unasserted thought in this case:

• Zula: [looking at some zebras in the zoo] There are some zebras over there.
• Asshole: They look like zebras. But who knows? Maybe they're cleverly disguised mules.
• Zula: [thinking to herself] What an asshole. I know that they're zebras.

Zula's thought won't mislead Asshole or anybody else, so Duncan's story can't show why it's inappropriate. But it seems intuitively problematic in the same way her original assertion is. Similarly, there seems to be impropriety about Moorean assertions in third-personal contexts where one won't mislead. Suppose that you and I know full well that Zula can't tell the difference between a real zebra and a fake zebra; we also know full well that she is looking at a real zebra right now. Consider this:

• Zula: [looking at some zebras in the zoo] There are some zebras over there.
• Asshole: They look like zebras. But who knows? Maybe they're cleverly disguised mules.
• Me: [to you, out of earshot of Z and A] Zula knows that they're zebras.

My assertion seems problematic in the same way Zula's original one does; but I do not mislead anyone. (We could also consider, for this point, a version of the first-personal case where it is stipulated to be common knowledge that Zula lacks the discriminatory ability in question.)

Here is one more observation about the case. Suppose nobody says anything about knowledge, as in this variant:

• Zula: [looking at some zebras in the zoo] There are some zebras over there.
• Asshole: They look like zebras. But maybe they're cleverly disguised mules.
• Zula: They are zebras.

Insofar as I can feel the force of Duncan's suggestion that Zula's original final utterance—'I know that they're zebras—implicates that she has special abilities to rule out fakes, I think the same applies here. But if so, I think that this may show that even if Duncan has identified something wrong with the knowledge assertion, he hasn't identified everything wrong with it. For we have no inclination whatsoever to think that Zula speaks falsely in asserting, even in the face of the skeptical challenge, that there are zebras. The case is very different for her self-ascription of knowledge. The intuition is not merely that she shouldn't say she has knowledge; it's that she doesn't. (Indeed, I think the intuition is that it'd be fine for her to assert that she doesn't have knowledge.) Since there seems to be a special phenomenon about knowledge ascriptions, the pragmatic story will only work if it is particular to knowledge ascriptions. But I don't think it is; once the challenge has been made, an outright assertion of the proposition that was challenged does—so far as I can tell, in exactly the same way a bare knowledge ascription does—in some sense convey that one has the ability to answer the challenge.

More thoughts on more central elements of Duncan's very interesting book to follow. I started here for the simple reason that  it was freshest in my mind when I finished the book today.