August 22, 2004

Inference, Perception, or Something Else?

Read this passage from Ruth Rendell's Talking to Strange Men (the recommended way to do this is by reading the whole book. It's one of Rendell's best, which means it is one of the best mystery novels ever). Part III, Chapter 6:

A middle-aged ordinary-looking man and a young pretty woman. How had he known they were police? For he did know it from the moment they stepped out of that anonymous lamp-less unmarked car. Perhaps it was because the driver remained behind, impassive at the wheel, reminding John of police drivers from that time sixteen years before [a previous occasion on which John's house had been visited by police].

Leaving aside the use of "know" here, I want to ask: What is the basis for John's belief that they are police?

Is John's belief simply acquired through perception? I think that this is harder to sustain in this case than in the well-known cloud-chamber case, in which we say that a properly trained physicist can simply see a thingumbobby particle in the tracks of a cloud chamber, where the layperson would see only tracks in clouds. John doesn't have any sort of special training here. The physicist presumably doesn't go on to ask herself, "How do I know that that's a thingumbobby? Because it left this kind of track."

Is John's belief inferred, with "The driver remained behind" as a premise? Obviously it's not a conscious inference; John doesn't even think about the driver until he's already identified the two coming up the walk as police. If it's subconscious inference, the inference seems to be buried very deep.

Or is John's belief neither perceptual or inferential, but one which depends on perception and on the fact that the driver stays behind in some third way? If so, it would be nice to have an account of what that third way is.

To some extent the issue here shouldn't be to slot this belief into some neat category. It should be to say--is it more like cases that are obviously cases of perception or more like cases that are obviously cases of inference? Here I'm inclined to say this: Obvious perception happens all the time; I'm forming a lot of plain unquestionable perceptual beliefs right now, as I look out the window. Obvious inference may be pretty rare; most of us don't go through life constantly saying to ourselves "This, therefore that." But we may more often say to ourselves. "This, that."

That is to say: We may note one fact, and then note another fact, which in fact is supported by the first fact. That's what Fred is doing in the following passage:

Fred saw the middle-aged man and the young woman coming up the walk. The driver remained behind, impassive at the wheel. They were the police, he thought. That was how the driver had behaved sixteen years before.

I think Fred's case is very close to an obvious case of inference; if we change a sentence to "So they must be the police" it becomes an obvious case of inference. And I think John's case is very close to Fred's. John and Fred both have a belief P that supports a belief Q, but whereas Fred thinks first P and then Q, John's belief that P does not become conscious until he has already formed the belief that Q.

(I could be getting into a sorites here; it shouldn't be hard to form a chain of cases, each very like the one before, that culminate in a case that's obviously a perceptual belief. Left to the reader.)

I'm thinking about this because people thinking about testimony often worry about whether testimonial beliefs are inferential, or directly obtained through testimony. Here, for instance, I think part of what Jon Kvanvig is worried about is that a belief will not be purely testimonial if it is obtained by inference from another belief (in Jon's case, one that overrides a defeater of the testimony). My take on this is that purely testimonial beliefs can be like John's (in the Rendell book); so if John's belief is inferential, purely testimonial beliefs can be inferential as well. The hearer's beliefs in the teller's honesty and authority can stay in the background, as John's memory of the previous police driver stays in the background until after he has realized that it is the police visiting him.

(This is a follow-up to this post, kinda.)

Posted by Matt Weiner at August 22, 2004 06:08 PM

I say perceptual. Whether a belief is inferential seems to me to depend on the justification the subject would give. There are many cases of perceptually-based belief where we can take a stab at articulating the perceptual features on which it (causally) depends, but really are only speculating, and we are not giving the premise of an argument, that's for sure. ("That sounds like Mozart" "What makes you say that?" "Uh, well, the arpeggios like that and stuff...")

This narrative does not make clear whether the subject himself could state the thing about the driver remaining behind, but it doesn't seem to make a difference. All he really knows is that they looked like police to him.

I guess it does suggest it is a psychological fact about him that something about their look reminded him of police he saw years ago, and he might even be able to correctly say what it is. "They way they ... reminds me of police I saw years ago; therefore, they are police" is an argument, though not a good one. It doesn't seem right to say he is relying on that argument as opposed to just "they look like police to me".

I think there could be similar cases in which "inferential" would be the right answer. ("Hmm, something's funny about them, what is it ... Aha! they look just like those police I saw years ago. They must be coppers as well!") Here he does not just see them as police but has to rely on a bit of reasoning to get to a non-obvious conclusion.

Posted by: Anders Weinstein at August 24, 2004 12:01 PM

That seems like a pretty strict restriction on inferential belief--I'm not saying it's wrong, it just seems strict. If I infer something, and then forget the premise, is my belief no longer inferential--since I can't give the premise as a justification? Perhaps. (I also note that you move from "not inferential" to "perceptual"....)

I take the whole passage to be in free indirect discourse, so that everything in it is roughly like a thought that occurs to John (perhaps slightly subconsciously).

Posted by: Matt Weiner at August 24, 2004 03:52 PM