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.

Earman is a philosopher and the book has gotten positive reviews from other philosophers. I don't know what else to say in that regard.

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.

Hrrm? You mentioned professionals first. I'm not sure why you are now objecting to the use of professionals as a relevant category.

That is a major point for scientific research where the problem "how do we use evidence?" is important. And the answer is "criticisms can refer to evidence". Note by "science" here I mean any empirical field. What do you do in non-scientific fields? You simply make criticisms that don't refer to evidence. Same method, just missing one type of criticism which is rather useful in science but not fundamental to the methodology

I'm not at all convinced that this is what Popper intended (but again I've only read LScD) but if this is accurate then Popper isn't just wrong in an interesting way but is just wrong. Does one mean for example to claim that pure mathematics works off of criticism? I'm a mathematician. We don't do this. Moreover, it isn't clear what it would even mean for us to try to do this as our primary method of inquiry. Are we supposed to spend all our time going through pre-existing proofs trying to find holes in them?

He has like 20 books. There's way more to it. When one reads a lot of them, a whole worldview comes across that is very hard to understand from just a couple books.

Yes, and I'm quite sure that I get much more of a worldview if I read all of Hegel rather than just some of it. That doesn't mean I need to read all of it. Similar remarks would apply to Aquinas or more starkly the New Testament. Do you need to read all of the New Testament to decide that Christianity is bunk? Do you need to read the entire Talmud to decide that Judaism is incorrect? But you get a whole worldview that you don't obtain from just reading the major texts.

The short answer is: since we don't care to have justified foundations, you can discuss it any way you like. You can say it's bad because it hurts people. You can say it's good because it prevents overpopulation. You can say it's bad because it's mean. These kinds of normal arguments, made by normal people, are not deemed automatically invalid and ignored. Many of them are indeed mistakes. But some make good points

Right, and then we just the criticism "why bother" or "and how does that maximize the number of paperclip in the universe?" Or one can say "mean" "good" bad" are all hideously ill-defined. In any event, does it not bother you that you are essentially claiming that your moral discussion with your great epistemological system looks just like a discussion about morality by a bunch of random individuals? There's nothing in the above that uses your epistemology in any substantial way.

Are you really telling me that you can prove something, then take the conclusion, redefine a term, and work with that, and consider it still proven? You could only do that if you created a second proof that the change doesn't break anything, you can't just do it.

Right! And conveniently in the case Popper cares about you can prove that.

Popper doesn't appreciate what you can do with measure theory and L_p spaces

Would you understand if I said this has no relevance at all to 99.99% of Popper's philosophy? Note that his later books generally have considerably less mention of math or logic.

Do you mean understand or do you mean care? I don't understand why you are making this statement given that my remark was addressing the question you asked of whether I had specific problems with Popper's handling of Bayesianism in LScD. This is a specific problem there.

As I tried to say (and probably explained really poorly- sorry!), the LW consensus is that morality is not objective. Therefore, the idea of figuring out what good moral values would be is, according to moral non-realism, impossible: any decision about what a good moral value is must rely on your pre-existing values, if an objective morality is not out there to be discovered. Using this as a criticism of Bayesianism is sorta like criticizing thermodynamics because it claims it's impossible to exactly specify the position and velocity of each particle: not only is the criticism unrelated to the subject matter, but satisfying it would require the theory to do something that is to the best of our knowledge incorrect.

I think you regard innate/genetic ideas as important. I do not. Because people are universal knowledge creators, and can change any idea they start with, it doesn't matter very much.

You misunderstand. I bring it up as a model of learning, and my choice was based on your own remarks. You said that knowledge is created by an evolutionary process. That way of putting it suggests an analogy with Darwin's theory of evolution as proceeding by random variation and natural selection. And indeed there is an analogy between Popper's conjectures and refutations and variation and natural selection, and it is this: a conjecture is something like variation (mutation), and refutation is something like natural selection.

However, what I found was that the closer I looked at knowledge which is actually acquired through natural selection - what we might call innate knowledge or instinctive knowledge - the more the process of acquisition resembled Bayesian updating rather than Popperian conjecture and refutation. I explained why.

In Bayesian updating, there are competing hypotheses, and the one for which actual events are less of a surprise (i.e., the hypothesis Hi for which P(E|Hi) is higher) is strengthened relative to the one for which events are more of a surprise. I find a parallel to this in competition among alleles under natural selection, which I described.

Essential to Bayesian updating is the coexistence of competing hypotheses, and essential to natural selection is the coexistence of competing variants in a species. In contrast, Popper talks about conjecture and refutation, which is a more lonely process that need not involve more than one conjecture and a set of observations which have the potential to falsify it. Popper talks about improving the conjecture in response to refutation, but this process more resembles Lamarckian evolution than Darwinian evolution, because in Lamarckian evolution the individuals improve themselves in response to environmental challenges, much as Popper would have us improve our conjectures in response to observational challenges. Also, in Lamarckian evolution, as in the Popperian process of conjecture and refutation, competing variants (compare: competing hypotheses) do not play an essential role (though I'm sure they could be introduced). Rather, the picture is of a single animal (compare: a single hypothesis) facing existential environmental challenges (compare: facing the potential for falsification) improving itself in response (which improvement is passed to offspring).

The Popperian process of conjecture, refutation, and improvement of the conjecture, can as it happens be understood from a Bayesian standpoint. It does implement Bayesian updating in a certain way. Specifically, when a particular conjecture is refuted and the scientist modifies the conjecture - at that point, there are two competing hypotheses. So at that point, the process of choosing between these two competing hypotheses can be characterized as Bayesian updating. The less successful hypothesis is weakened, and the more successful hypothesis is strengthened.

In short, if you want to take seriously the analogy that does exist between evolution through natural selection and knowledge acquisition of whatever type, then you may want to take a closer look at Bayesian updating as conforming more closely to the Darwinian model.

For sake of argument we say that the plant requires a rare and unstable isotope to get started. Earth's entire supply is contained in the plant and will decay in 24 hours.

I could also ask you a similar dilemma, but this time there is only one theory which acknowledges that whether the plant works or creates a black hole depends on a single quantum event, which has a 50% chance of going either way. What do you do? If you wouldn't launch I can ask the same question but now there's only a 25% chance of a black hole, and so on until I learn the ratio of the utility values that you assign to "post scarcity future" and "extinction of humanity". This might for example tell me that the chance of a black hole has to be less than 30% for you to press the button.

Then I ask you the original dilemma, and learn whether the probability you assign to theory X is above or below 70%. If I have far too much time on my hands I can keep modifying the dilemma with slightly altered pay-offs until I pinpoint your estimate.

This avoids the question. If it helps, try to construct a version of this in the least convenient possible world. For example, one obvious thing to do would be that something about theory X means the plant can only be turned on at a certain celestial conjunction (yes, this is silly but it gets the point across. That's why it is a least convenient world) and otherwise would need to wait a thousand years.

One can vary the situation. For example, it might be that under theory X, medicine A will save a terminally ill cancer patient, and under theory Y, medicine B will save them. And A and B together will kill the patient according to both theories.

To give a simple example, consider flipping a coin. You observe HHH. Is this a fair coin? or a double-headed one? or a biased coin? Different theories describe these situations, and you could be asked to bet on them. Imagine you then further observe HHHH - making a total of HHHHHHH. This makes your estimate of the chances of the "double-headed coin" hypothesis go up. Other hypotheses may increase in probability too - but we are not troubled by there being an infinity of them, since we give extra weight to the simpler ones, using Occam's razor.