Is there some reason I should take David Chapman as particularly authoritative? Why do you find his disagreement with senior LW people of particular note?
Because senior LW people spent effort in replying to him. The post lead to LW posts such as what bayesianism taught me. Scott Alexander wrote in response: on first looking into chapmans pop-bayesianism. Kaj Sotala had a lively exchange in the comments of that article.
I think in total that exchange provides a foundation for clearing the question of what Bayesianism is. I do consider that an important question.
As far as authority goes David Chapman did publish academic papers about artificial intelligence. He did develop solutions for previously unsolved AI problems. When he says that there's no sign of Bayes axiom in the code that he used to solve an AI problem he just might be right.
Funny, I've been making that point for a while. I doubt that it applies to Dennett, but the other guys can't seem to conceive of truth beyond correspondence.
Dennett is pretty interesting. Instead of asking what various people mean when they say consciousness he just assumes he knows and declares it nonexistent. The idea that maybe he doesn't understand what other people mean with the term doesn't come up in his thought.
Dennett writes about how detailed visual hallucinations are impossible. I do have had experiences where what I visually perceived didn't change much whether or not I closed my eyes. It was after I spent 5 days in artificial coma. I know two additional people who I meet face to face who have had similar experiences.
I also have access to various accounts of people hallucinating stuff in other context via hypnosis. My own ability let myself go is unfortunately not good, so I still lack some first hand accounts of some other hallucinations.
A week ago I spoke at our local LW meetup with someone who said that while "IQ" obviously exists "free will" obviously doesn't. At that point in time I didn't know exactly how to resolve the issue but it seems to me that those are both concept that exist somehow on the same level. You won't find any IQ atoms and you won't find any free will atoms but they are still mental concepts that can be used to model things about the real world.
That a problem that arises by not having a well defined idea of what it means for concepts to exist. In practice that leads to terms like depression getting defined by committee and written down in the DSM-V and people simply assuming that depression exists without asking themselves in what way it exists. If people would ask themselves in what way it exist that might provide ground for a new way to think about depression.
But if it's a matter of people being open to changing their world view, to even understanding that they have one, and other people have other world views, it's Korzybski they need to read, not Jaynes.
The problem with Korzybski is that he's hard to read. Reading and understanding him, is going to be hard work for most people who are not exposed to that kind of thinking.
What might be more readable is Barry Smith's paper "Against Fantology". It's only 20 pages.
the idea being that it would be possible to save the fantological doctrine by denying the existence of those entities which cause it problems. Many heirs of the fantological world view have in this way found it possible to avoid the problems raised for their doctrines by apparent examples of true predications in the category of substance by denying the existence of substances.
I think that's what the New Atheists like Dennett do. They simply pretend that the things that don't fit in their worldview don't exist.
I think you're being unfair to Dennett. He actually has availed himself of the findings of other fields, and has been at the consciousness shtick for decades. He may not agree, but it's unlikely he is unaware.
And when did he say consciousness was nonexistent?
Cite? That seems a rather odd thing for him to say, and not particularly in his ideological interests.
Dennett writes about how detailed visual hallucinations are impossible.
Cite here? Again, except for supernatural bogeymen, my experience of him is that he recognizes that all sorts of mental ev...
I used to teach logic to undergraduates, and they regularly made the same simple mistake with logical quantifiers. Take the statement "For every X there is some Y such that P(X,Y)" and represent it symbolically:
∀x∃y P(x,y)
Now negate it:
!∀x∃y P(x,y)
You often don't want a negation to be outside quantifiers. My undergraduates would often just push it inside, like this:
∀x∃y !P(x,y)
If you could just move the negation inward like that, then these claims would mean the same thing:
A) Not everything is a raven: !∀x raven(x)
B) Everything is not a raven: ∀x !raven(x)
To move a negation inside quantifiers, flip each quantifier that you move it past.
!∀x∃y P(x,y) = ∃x!∃y P(x,y) = ∃x∀y !P(x,y)
Here's the findings of a 1982 article [1] from JAMA Psychiatry (formerly Archives of General Psychiatry), back in the days when the medical establishment was busy denouncing the Feingold diet:
Now pay attention; this is the part everyone gets wrong, including most of the commenters below.
The methodology used in this study, and in most studies, is as follows:
People make the error because they forget to explicitly state what quantifiers they're using. Both the t-test and the F-test work by assuming that every subject has the same response function to the intervention:
response = effect + normally distributed error
where the effect is the same for every subject. If you don't understand why that is so, read the articles about the t-test and the F-test. The null hypothesis is that the responses of all subjects in both groups were drawn from the same distribution. The one-tailed versions of the tests take a confidence level C and compute a cutoff Z such that, if the null hypothesis is false,
P(average effect(test) - average effect(control)) < Z = C
ADDED: People are making comments proving they don't understand how the F-test works. This is how it works: You are testing the hypothesis that two groups respond differently to food dye.
Suppose you measured the number of times a kid shouted or jumped, and you found that kids fed food dye shouted or jumped an average of 20 times per hour, and kids not fed food dye shouted or jumped an average of 17 times per hour. When you run your F-test, you compute that, assuming all kids respond to food dye the same way, you need a difference of 4 to conclude with 95% confidence that the two distributions (test and control) are different.
If the food dye kids had shouted/jumped 21 times per hour, the study would conclude that food dye causes hyperactivity. Because they shouted/jumped only 20 times per hour, it failed to prove that food dye affects hyperactivity. You can only conclude that food dye affects behavior with 84% confidence, rather than the 95% you desired.
Finding that food dye affects behavior with 84% confidence should not be presented as proof that food dye does not affect behavior!
If half your subjects have a genetic background that makes them resistant to the effect, the threshold for the t-test or F-test will be much too high to detect that. If 10% of kids become more hyperactive and 10% become less hyperactive after eating food coloring, such a methodology will never, ever detect it. A test done in this way can only accept or reject the hypothesis that for every subject x, the effect of the intervention is different than the effect of the placebo.
So. Rephrased to say precisely what the study found:
Converted to logic (ignoring time):
!( ∀child ( eats(child, coloring) ⇨ behaviorChange(child) ) )
Move the negation inside the quantifier:
∃child !( eats(child, coloring) ⇨ behaviorChange(child) )
Translated back into English, this study proved:
However, this is the actual final sentence of that paper:
Translated into logic:
!∃child ( eats(child, coloring) ⇨ hyperactive(child) ) )
or, equivalently,
∀child !( eats(child, coloring) ⇨ hyperactive(child) ) )
This refereed medical journal article, like many others, made the same mistake as my undergraduate logic students, moving the negation across the quantifier without changing the quantifier. I cannot recall ever seeing a medical journal article prove a negation and not make this mistake when stating its conclusions.
A lot of people are complaining that I should just interpret their statement as meaning "Food colorings do not affect the behavior of MOST school-age children."
But they didn't prove that food colorings do not affect the behavior of most school-age children. They proved that there exists at least one child whose behavior food coloring does not affect. That isn't remotely close to what they have claimed.
For the record, the conclusion is wrong. Studies that did not assume that all children were identical, such as studies that used each child as his or her own control by randomly giving them cookies containing or not containing food dye [2], or a recent study that partitioned the children according to single-nucleotide polymorphisms (SNPs) in genes related to food metabolism [3], found large, significant effects in some children or some genetically-defined groups of children. Unfortunately, reviews failed to distinguish the logically sound from the logically unsound articles, and the medical community insisted that food dyes had no influence on behavior until thirty years after their influence had been repeatedly proven.
[1] Jeffrey A. Mattes & Rachel Gittelman (1981). Effects of Artificial Food Colorings in Children With Hyperactive Symptoms: A Critical Review and Results of a Controlled Study. Archives of General Psychiatry 38(6):714-718. doi:10.1001/archpsyc.1981.01780310114012.
[2] K.S. Rowe & K.J. Rowe (1994). Synthetic food coloring and behavior: a dose response effect in a double-blind, placebo-controlled, repeated-measures study. The Journal of Pediatrics Nov;125(5 Pt 1):691-8.
[3] Stevenson, Sonuga-Barke, McCann et al. (2010). The Role of Histamine Degradation Gene Polymorphisms in Moderating the Effects of Food Additives on Children’s ADHD Symptoms. Am J Psychiatry 167:1108-1115.