Monday, November 1, 2010

TSRM's Shark Example 4

Sharks electrically detect things to eat and things that impede locomotion (Kalmijn, 1974). An edible living thing such as a flatfish differs in ionic com• position from the surrounding water, producing a bioelectric field partially modulated in the rhythm of the living thing's respiratory movements. A flatfish that has buried itself in the sand will be detectable by a shark swimming just above it. Reproducing the bioelectric field of the flatfish artificially, bypassing a current between two electrodes buried in the sand, invites the same predatory behavior. The shark digs tenaciously at the source of the field departing from the site when the act fails to reveal an edible thing (Kalmijn, 1971). Now there is no intelligible sense in which it can be claimed that the source ought to have appeared inedible if the shark's perception were free of error and if the shark's perception of affordances were direct. In the niche of the shark 'an edible thing' and 'electric field of, say, type F' are nomically related. To predicate of the shark (a) 'detects electric field of type F' and (b) 'takes to be an edible thing' is not to refer to two different states of affairs, one (viz. (b)) that is reached from the other (viz. (a)) by an inference. Rather, it is to make reference in two ways to a single state of affairs of the shark-niche system. The linking of (a) and (b) is not something that goes on in the "mind" of the shark, as the Establishment would have it. The linking of (a) and (b) is in the physics of an ecological world, namely, that system given by the complementation of the shark and its niche.
     But what of the shark's actions? Should we not classify them as being in error, as being wrong? After all, the source of the electric field proved not to be an edible thing. Given the nomic relation between 'electric field of type F' and 'edible' there is no intelligible sense in which it can be said that the shark's act of investigating the source of the field was wrong. The wrong action for the shark, given its niche and its appetite, would be not investigating the source of the field.  (Turvey, Shaw, Reed, & Mace, 1981, pp. 276-7).
Consider, now, the final paragraph.  TSRM note (correctly, I believe) that we would not say that the actions are mistaken in the non-standard environments. I think the shark's actions are appropriate given that it takes there to be an edible thing.  But, if it takes things to be that way, then it's taking things to be some way that they are not.  That is, what it takes to be true is, in fact, false.  But, false takings are a problem for the EP approach.

TSRM might claim that, in the non-standard environment, the shark does not take there to something edible.  But, that would conflict with their claim that (a) and (b) are the same state of affairs.


  1. Turvey et al explicitly do not make the latter claim, as is pretty clear in that last paragraph.

    And the point is (still!) that the shark has no basis for knowing about the error. It can only 'take there to be an edible fish there', because that's what the available information (initially) specifies. (Further exploration will reveal the problem.)

    So you can describe (from your privileged, 3rd person perspective) the shark as being in error all you like, but you will be making the psychologist's fallacy. Your description will always be the incorrect way to describe anything about the perceptual state of the shark, and thus of no use in a theory of perception, which is what TSRM are trying to lay a foundation for.

  2. "And the point is (still!) that the shark has no basis for knowing about the error. "

    Agreed, but the shark is still in error. The perceptual state of the shark according to TSRM is that it takes there to be something edible. Saying that the shark is in error is to say something about the relationship between the shark's perceptual state and the world.

    But, this line about describing beliefs as in error is not TSRM's. At some point, there has to be some theory of false belief, right?

  3. Or, think of it this way.

    I would put in the shark's cartoon "thought bubble" : Edible thing there.

    I would not put in the shark's cartoon thought bubble": I am in error in taking there to be an edible thing there.

  4. So, let me go back to your first broaching of this "psychologist's fallacy" line.

    "At the point where he detects the field specifying 'fish', he isn't in error; perhaps more specifically, he can't know he's in error, and the only person able to describe the situation this way is the evil psychologist who has some privileged access to the ruse.

    From the perspective of the evil psychologist, that is a way to talk about the shark. But actually this smacks of James' 'psychologist's fallacy'; taking your description and making it the explanation. "

    So, you seem to be suggesting that when *I* talk about the shark being in error I am committing this fallacy, but when *you* talk about the shark not being in error, you are not committing the fallacy. Both seem to me equally to be third person perspectives and pretty unobjectionable. What you seem to object to is merely *my* third person perspective.

  5. I would put in the shark's cartoon "thought bubble" : Edible thing there.

    But the TSRM analysis, that it's incorrect to say the shark is in error, isn't taking a 3rd person perspective. It's explicitly taking the shark's perspective, ie the perspective required of a theory of perception.

  6. "it's incorrect to say the shark is in error, isn't taking a 3rd person perspective"

    I'm not saying that. When I say that the shark is in error that is indeed my third person perspective. And, I'm not confusing that with the shark's first person perspective.

    I think I'm clear on what the shark's first person perspective is and what my third person perspective is. The problem for TSRM is that from the third person perspective they have a tough time explaining why the shark stop digging when it both takes there to be a fish present (because it detects F) and takes there not to be a fish present (because it has dug around in the sand). How do they explain the shark's resolution of its conflicting takes?

  7. But they aren't interested in explaining things from a third person perspective. A theory of perception has to account for behaviour from the first person perspective.

  8. Right, but they don't have a first person explanation. The problem is *the shark* takes there to be a fish and *the shark* takes there not to be a fish. So, why does the shark quit digging? There is no first person account of how the shark resolves this.

    A separate problem is the problem of false takings, which EP seems not to like.

  9. "Summary: illusions do pose an important question to direct realist accounts of perception that must be answered, but the challenge has been met; illusions create true visual experiences under artificially constrained circumstances "

    Illusions create true visual experiences? Why don't you think you are committing the psychologist's fallacy?

  10. Because I have an account of how the visual experience arises that accounts for why you see what you see in that case? It's first person and doesn't include anything the perceiver has no basis to know.