I was directed to this book (http://www-biba.inrialpes.fr/Jaynes/prob.html) in conversation here:
http://lesswrong.com/lw/3ox/bayesianism_versus_critical_rationalism/3ug7?context=1#3ug7
I was told it had a proof of Bayesian epistemology in the first two chapters. One of the things we were discussing is Popper's epistemology.
Here are those chapters:
http://www-biba.inrialpes.fr/Jaynes/cc01p.pdf
http://www-biba.inrialpes.fr/Jaynes/cc02m.pdf
I have not found any proof here that Bayesian epistemology is correct. There is not even an attempt to prove it. Various things are assumed in the first chapter. In the second chapter, some things are proven given those assumptions.
Some first chapter assumptions are incorrect or unargued. It begins with an example with a policeman, and says his conclusion is not a logical deduction because the evidence is logically consistent with his conclusion being false. I agree so far. Next it says "we will grant that it had a certain degree of validity". But I will not grant that. Popper's epistemology explains that *this is a mistake* (and Jaynes makes no attempt at all to address Popper's arguments). In any case, simply assuming his readers will grant his substantive claims is no way to argue.
The next sentences blithely assert that we all reason in this way. Jaynes' is basically presenting the issues of this kind of reasoning as his topic. This simply ignores Popper and makes no attempt to prove Jaynes' approach is correct.
Jaynes goes on to give syllogisms, which he calls "weaker" than deduction, which he acknowledges are not deductively correct. And then he just says we use that kind of reasoning all the time. That sort of assertion only appeals to the already converted. Jaynes starts with arguments which appeal to the *intuition* of his readers, not on arguments which could persuade someone who disagreed with him (that is, good rational arguments). Later when he gets into more mathematical stuff which doesn't (directly) rest on appeals to intution, it does rest on the ideas he (supposedly) established early on with his appeals to intuition.
The outline of the approach here is to quickly gloss over substantive philosophical assumptions, never provide serious arguments for them, take them as common sense, do not detail them, and then later provide arguments which are rigorous *given the assumptions glossed over earlier*. This is a mistake.
So we get, e.g., a section on Boolean Algebra which says it will state previous ideas more formally. This briefly acknowledges that the rigorous parts depend on the non-rigorous parts. Also the very important problem of carefully detailing how the mathematical objects discussed correspond to the real world things they are supposed to help us understand does not receive adequate attention.
Chapter 2 begins by saying we've now formulated our problem and the rest is just math. What I take from that is that the early assumptions won't be revisted but simply used as premises. So the rest is pointless if those early assumptions are mistaken, and Bayesian Epistemology cannot be proven in this way to anyone who doesn't grant the assumptions (such as a Popperian).
Moving on to Popper, Jaynes is ignorant of the topic and unscholarly. He writes:
http://www-biba.inrialpes.fr/Jaynes/crefsv.pdf
> Karl Popper is famous mostly through making a career out of the doctrine that theories may not be proved true, only false
This is pure fiction. Popper is a fallibilist and said (repeatedly) that theories cannot be proved false (or anything else).
It's important to criticize unscholarly books promoting myths about rival philosophers rather than addressing their actual arguments. That's a major flaw not just in a particular paragraph but in the author's way of thinking. It's especially relevant in this case since the author of the books tries to tell us about how to think.
Note that Yudkowsky made a similar unscholarly mistake, about the same rival philosopher, here:
http://yudkowsky.net/rational/bayes
> Previously, the most popular philosophy of science was probably Karl Popper's falsificationism - this is the old philosophy that the Bayesian revolution is currently dethroning. Karl Popper's idea that theories can be definitely falsified, but never definitely confirmed
Popper's philosophy is not falsificationism, it was never the most popular, and it is fallibilist: it says ideas cannot be definitely falsified. It's bad to make this kind of mistake about what a rival's basic claims are when claiming to be dethroning him. The correct method of dethroning a rival philosophy involves understanding what it does say and criticizing that.
If Bayesians wish to challenge Popper they should learn his ideas and address his arguments. For example he questioned the concept of positive support for ideas. Part of this argument involves asking the questions: 'What is support?' (This is not asking for its essential nature or a perfect definition, just to explain clearly and precisely what the support idea actually says) and 'What is the difference between "X supports Y" and "X is consistent with Y"?' If anyone has the answer, please tell me.
As to a professional, I already referred you to Earman. Incidentally, you seem to be narrowing the claim somewhat. Note that I didn't say that the set of major ideas in epistemology isn't small, I referred to the much larger class of philosophical ideas (although I can see how that might not be clear from my wording). And the set is indeed very large. However, I think that your claim about "after Aristotle" is both wrong and misleading. There's a lot of what thought about epistemological issues in both the Islamic and Christian worlds during the Middle Ages. Now, you might argue that that's not helpful or relevant since it gets tangled up in theology and involves bad assumptions. But that's not to say that material doesn't exist. And that's before we get to non-Western stuff (which admittedly I don't know much about at all).
(I agree when you restrict to professionals, and have already recommended Earman to you.)
This is a deeply puzzling set of claims. First of all, a major point of his epistemological system is falsfiability based on data (at least as I understand it from LScD). How that would at all interact with moral issues is unclear to me. Indeed, the semi-canonical example of a non-falsifiable claim in the Popperian sense is Marxism, a set of ideas that has a large set of attached moral claims.
I also don't see how this works given that moral claims can always be criticized by the essential sociopathic argument "I don't care. Why should you?" Obviously, that line of thinking can be/should be expanded. To use your earlier example, how would you discuss "murder is wrong" in a Popperian framework? I would suggest that this isn't going to be any different than simply discussing moral ideas based on shared intuitions with particular attention to the edge cases. You're welcome to expand on these claims, but right now, nothing you've said in this regard is remotely convincing or even helpful since it amounts to just saying "well, do the same thing."
I'm going to be obnoxious and quote a friend of mine "Everyone who understands Christianity is a Christian." I don't have any deep examples of other individuals although I would tentatively say that I understood Popper's views in Logic of Scientific Discovery just fine.
Sure. The most obvious one is when he is discussing the law of large numbers and frequentist v. Bayesian interpretations (incidentally to understand those passages it is helpful to note that he uses the term "subjective" to describe Bayesians rather than Bayesian which is consistent with the language of the time, but in modern terminology has a very different meaning (used to distinguish between subject and objective Bayesians)). In that section he argues that (I don't have the page number unfortunately since I'm using my Kindle edition. I have a hard copy somewhere but I don't know where) that "it must be inadmissable to give after the deduction of Bernoulli's theorem a meaning to p different from the one which was given to it before the deduction." This is, simply put, wrong. Mathematicians all the time prove something in one framework and then interpret it in another framework. You just need to show that all the properties of the relevant frameworks overlap in sufficiently non-pathological cases. If someone wrote this as a complaint about say using the complex exponential to understand the symmetries of the Euclidean plane, we'd immediately see this as a bad claim. There's an associated issue in this section which also turns up but it is more subtle; Popper doesn't appreciate what you can do with measure theory and L_p spaces and related ideas to move back and forth between different notions of probability and different metrics on spaces. That's ok, it was a very new idea when he wrote LScD (although the connections were to some extent definitely there). But it does render a lot of what he says simply irrelevant or outright wrong.
Which you stated you had not read. I have rather low standards for recommendations of things to read, but "I never read it myself" isn't good enough.
I don't agree with "restrict to professionals". How is it to be determined who is a professional? I don't want to set up arbitrary, authoritative criteria for dismissing ideas based on their source.
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