Monday, June 02, 2008

Vallicella on the Scientific Objection to Direct Realism

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At 6/03/2008 01:07:00 PM , Blogger Blue Devil Knight said...

The analogy between the 'distance from' relation and the 'perception of' that Butch provides is interesting and clever.

As Butch says (quoted by William A. Maverick), "[T]he fact that I come to be 240 miles from Chicago as a result of a fairly long and complex causal process of driving does not entail that this end-result, my being 240 miles from Chicago, is not my being in a direct spatial relation to Chicago . . ." (7-8)

This is a clever way to try to block any facile move from the claim 'Relation between X and Y is explained by a complicated causal process' to the claim 'X and Y cannot be in a direct relation (a diadic relation).'

However, things are a little tricky. For one, it isn't clear how dreams and hallucinations can be accommodated. As I said in comment to previous post, those phenomena are the direct realism killers for me. Killers unless he wants to say the relationship is between subject and intentional object, but then we don't have realism anymore. It would perhaps be a species of idealism.

But also, even focusing on the best-case scenario for direct realism, awake visual perception, he would also need to argue that the analogy with distance is apt. For instance, if I am 100 miles from Chicago, I am also 100 miles from an infinite number of other places. However, perceiving a dog has a specificity that distance doesn't have. What is to explain this specificity of content if not the causal or informational link with the thing in the world during normal perception? E.g., the fact that my eyes are directed in a certain way, that the perception disappears when the lights are turned off?

Perhaps to that he'd say, "Obviously, and these are all important conditions for perception, but in the act of perceiving, you have a direct relation with the thing perceived. All those details are like the details about my driving which are technically irrelevant for establishing the essence of the distance relation. Similarly, the fact that your eyes are directed at a particular dog, that your eyes are open, that the light is such-and-such, is certainly important for getting you into the state of directly perceiving something, but is not constitutive of the said perception."

So I'd say it seems he is trying to push DR in an interesting direction by pointing out that direct does not mean unmediated. The question then comes up, what is constitutive of direct perception, and how do you deal with illusions, hallucinations, and dream states in a way that avoids idealism?

In sum, while mediation is consistent with DR, why should we prefer DR to ~DR? William mentions this at the end of his post.

The arguments there against identity theory seem standard (a perceived pain is the wrong sort of thing to identify with a brain state), and we've hashed out these arguments a bit here already. I don't have the intuition that strongly, or at least don't have a non-question-begging argument that this is the case (it comes down to intuition snowballs about whether we'll end up with morning-star evening star type identities).

Plus the most popular version of naturalism about this stuff is not identity theory anyway, at least since 1980.

At any rate, DR and antirepresentationalism in general seem to be bogus. Brain in the vats are not just thought experiments. That's basically what you are when you are dreaming, and how do you get around the fact that the stuff doing the experiencing is intrinsic to the organism lying paralyzed, dreaming?

At 6/04/2008 08:01:00 PM , Blogger Darek Barefoot said...


Yea, but . . .

There's a coherence issue that arises from illusion in IR, also.

How can we say, "he had the illusion that he saw a dog" if properly speaking there is no "seeing a dog." To put in another way, given indirect realism perception is a
veridical illusion. But "veridical illusion" seems to fall short of coherence.

Suppose you are looking through a perfectly transparent window at certain objects. Being perfectly transparent, it is as if the glass were not there between you and the seen objects. But now the window gets scratched or smudged. The smudge reveals that you are looking through something. The presence of the glass is made evident.

To say that ordinarily the glass can be "looked through" as if it wasn't there is only coherent if there is the possibility of actually looking at the objects without the glass being there.

To carry forward the analogy, a scratch or smudge on the otherwise transparent sensory process would be a case of cognitive dissonance or evidence for illusion.

"Perceiving" would only seem to be possible "through" (mediated by) that process. But veridical perception demands "transparency" of the process, and transparency necessarily means "as if unmediated."

There appears to be an inescapable tension here between direct and indirect realism.

At 6/05/2008 07:30:00 AM , Blogger Blue Devil Knight said...

I'm not defending any alternative to DR, just exploring the good and the bad in DR as presented by Maverick Willy.

But getting at your problems, I agree that representations aren't visible. I see dogs, out there, in the world; I don't see representations of dogs. That's phenomenology. What explains that? Representations or something internal to my skin, as when I dream I see a dog.

At 6/05/2008 03:12:00 PM , Blogger Doctor Logic said...

BDK, you'll have to explain to me where the cleverness is in the Chicago argument.

As I see it, the problem with the Chicago analogy is this... What does it mean to be 240 miles from something? It implies a physical situation that can only be understood or explained in terms of the physical intermediaries. It means that walking or riding 240 miles takes me to a place with certain properties. We can't even speak about being 240 miles from Chicago without reference to the intermediate physics. This whole DR scheme looks to me like yet another linguistic trap. We're used to thinking about facts in an abstract fashion, divorced from our physical definitions. (If only people would not dismiss the achievements of the Vienna Circle so completely.)

There's also a powerful statistical argument for why DR is false. We have two possibilities. IR is compatible only (1:1) with our ability to disconnect perception from physics. DR is compatible with mediated and direct perceptions (2:1) of external facts. In every case, we find that perception is physically mediated. That means two things: 1) closure makes it terrifically unlikely that perception is direct, and 2) there are at least 2:1 odds that perception is mediated.

Darek, in this argument, I am agreeing that direct perception is a priori possible, but experience shows us that DR is a posteriori false.

At 6/05/2008 07:47:00 PM , Blogger Darek Barefoot said...


>>I am agreeing that direct perception is a priori possible<<

The problem is explaining how you can know what it you are referring to by "direct perception." It's as if we had an argument to the effect that movement is an impossiblity. How could we even know what movement is in that case?

Imagine a place like H. G. Wells' (I think it was Wells) Valley of the Blind, where for generations everyone is born profoundly blind. In such an isolated, profoundly blind community, how could questions ever arise as to whether such a thing as "sight" is possible? How could the proposition, "Sight is an impossibility" have any meaning to such people?

To say that direct perception of representations is possible, just not direct perception of the referents of the representations, only compounds the difficulties.

At 6/06/2008 09:30:00 AM , Blogger Doctor Logic said...


I don't follow your claim. It seems that your argument would mean we are always blind to any possibility we have yet to experience.

How about teleportation. It has never happened so far as we know. And yet I can easily imagine what experiences I would take as evidence for teleportation.

Similarly, if everyone were blind, I could easily imagine what experiences would cause me to believe in sight. I would have foreknowledge of my tactile environment without moving or touching things. I may not know what it feels like to have that ability, but that's a different story, isn't it?

At 6/06/2008 12:07:00 PM , Blogger Blue Devil Knight said...

DL: you raise interesting points to undermine his distance analogy. I think that, if someone were to really dig deep and think it through, you might be right. On the surface, though, it seems a clever way for him to make his point.

At 6/06/2008 12:09:00 PM , Blogger Darek Barefoot said...


We can rearrange perceptions into unrealistic arrangements. But this process only proceeds so far. When we get down to basic categories of perception, it's different.

I use the example of a unicorn. We can imagine a unicorn, but only because it can be broken down into conceptual pieces that are grounded in reality. Horses are real and horns are real, it's just the conjunction of them that is not.

I believe that perception of objects may well have fundamental status.

>>Similarly, if everyone were blind, I could easily imagine what experiences would cause me to believe in sight.<<

"Sight" as defined how? Detecting objects at a distance? You would think of hearing, and then picture "sight" as something sort of like hearing--only not exactly like it. Since you could not easily imagine sight itself, I doubt you could easily imagine what would make you believe in it.

You could imagine coming to believe in something like hearing only different in a crucial respect, but unless someone informed you about such a thing you probably wouldn't even get that far.

>>I may not know what it feels like to have that ability, but that's a different story, isn't it?<<

But in the context of our current discussion, we think we DO know what it feels like to perceive objects--as opposed to mere representations of objects. How can we know the "what it feels like" part without the ability??


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