Bayesianism versus Critical Rationalism

Jayson_Virissimo

I have just rediscovered an article by Max Albert on my hard drive which I never got around to reading that might interest others on Less Wrong. You can find the article here. It is an argument against Bayesianism and for Critical Rationalism (of Karl Popper fame).

Abstract:

Economists claim that principles of rationality are normative principles. Nevertheless,
they go on to explain why it is in a person’s own interest to be rational. If this were true,
being rational itself would be a means to an end, and rationality could be interpreted in
a non-normative or naturalistic way. The alternative is not attractive: if the only argument
in favor of principles of rationality were their intrinsic appeal, a commitment to
rationality would be irrational, making the notion of rationality self-defeating. A comprehensive
conception of rationality should recommend itself: it should be rational to be
rational. Moreover, since rational action requires rational beliefs concerning means-ends
relations, a naturalistic conception of rationality has to cover rational belief formation including
the belief that it is rational to be rational. The paper considers four conceptions
of rationality and asks whether they can deliver the goods: Bayesianism, perfect rationality
(just in case that it differs from Bayesianism), ecological rationality (as a version of
bounded rationality), and critical rationality, the conception of rationality characterizing
critical rationalism.

Any thoughts?

A good nutshell description of the type of Bayesianism that many LWers think correct is objective Bayesianism with critical rationalism-like underpinnings. Where recursive justification hits bottom is particularly relevant. On my cursory skim, Albert only seems to be addressing "subjective" Bayesianism which allows for any choice of prior.

4XiXiDu15y

For people like me who have no clue, if you scroll down a bit here there is a comparison (so you get a vague idea): * Subjective Bayesians emphasize the relative lack of rational constraints on prior probabilities. * Objective Bayesians (e.g., Jaynes and Rosenkrantz) emphasize the extent to which prior probabilities are rationally constrained. More here: And of course Critical rationalism: * Critical rationalism explicitly proposes a third decision rule for rational belief formation: it is rational to believe a hypothesis if it has so far withstood serious criticism better than its competitors.

5Matt_Simpson15y

I'll add that a decent summary of the position espoused in Where recursive justification hits bottom (linked in the grandparent) is that critical rationalism (or something like it) entails objective Bayesianism. It both entails the use of Baye's rule to update on information and it entails a set of correct priors.

1Jayson_Virissimo15y

Thanks for helping me realize that Critical Rationalism and Bayesianism can be compliments rather than substitutes.

2Elliot Temple15y

FYI that is a misleading statement of Critical Rationalism. For one thing, Popper was not a "belief philosopher" so he wouldn't have stated it quite like that. There are a lot of misleading statements about CR floating around. Most come from its opponents trying to make sense of it on their own terms. In trying to formulate it in a way that makes sense given their anti-CR premises, they change it. It's best to read primary sources for this.

It seems to think the problem of the priors does in Bayesianism :-(

Popper seems outdated. Rejecting induction completely is not very realistic.

2Jayson_Virissimo15y

Critical Rationalism has advanced somewhat since Popper. I think Hume would agree.

2timtyler15y

Not very significantly. The revolution happened mostly without them.

5Jayson_Virissimo15y

After reconsidering your statement, I have come to agree.

1Elliot Temple15y

Who do you think advanced CR? I think only David Deutsch has improved on Popper.

2Jayson_Virissimo15y

I had in mind Miller and Deutsch.

2Elliot Temple15y

Which Miller publication or argument?

5Jayson_Virissimo15y

Critical Rationalism: A Restatement and Defense and Out of Error: Further Essays On Critical Rationalism.

1Elliot Temple15y

Thanks I ordered them. I'd only read individual articles of his.

-2[anonymous]15y

Hume would agree because he never accepted the full force of his own argument. He couldn't imagine how people can create knowledge without induction even though he could see that induction is impossible. It took Popper to explain how knowledge can be created without induction.

To some extent our thought processes can certainly improve, however there is no guarantee of this

Yes, there is no guarantee. One doesn't need a guarantee for something to happen. And one can't have guarantees about anything, ever. So the request for guarantees is itself a mistake.

Ultimately, neither will ever be convinced of the other's viewpoint. If Alice conjectures anti-induction then she will immediately have a knock-down criticism, and vice versa for Bob and Induction. One of them has an irreversibly flawed starting point.

The sketches you give of Bob and Alice are not like real people. They are simplified and superficial, and people like that could not function in day to day life. The situation with normal people is different. No everyday people have irreversibly flawed starting points.

The argument for this is not short and simple, but I can give it. First I'd like to get clear what it means, and why we would be discussing it. Would you agree that if my statement here is correct then Popper is substantially right about epistemology? Would you concede? If not, what would you make of it?

Like it or not, you, me, Popper and every other human is an Alice.

That is a misconception. One of its prominent advocates was Hume. We do not dispute things like this out of ignorance, out of never hearing it before. One of the many problems with it is that people can't be like Alice because there is no method of induction -- it is a myth that one could possibly do induction because induction doesn't describe a procedure a person could do. Induction has no set of instructions to follow to offer.

That may sound strange to you. You may think it offers a procedure like:

1) gather data 2) generalize/extrapolate (induce) a conclusion from the data 3) the conclusion is probably right, with some exceptions

The problem is step 2 which does not how how to extrapolate a conclusion from a set of data. There are infinitely many conclusions consistent with any finite data set. So the entire procedure rests on having a method of choosing between them. All proposals made for this either don't work or are vague. The one I would guess you favor is Occam's Razor -- pick the simplest one. This is both vague (what are the precise guidelines for deciding what is simpler) and wrong (under many interpretations. for example because it might reject all explanatory theories b/c omitting the explanation is simpler).

Another issue is how one thinks about things he has no past experience about. Induction does not answer that. Yet people do it.

which of the following criticisms seems more logically appealing to you

I think they are both terrible arguments and they aren't how I think about the issue.

This might be correct, but there is a heavy burden of proof to show it.

The "burden of proof" concept is a justificationist mistake. Ideas cannot be proven (which violates fallibility) and they can't be positively shown to be true. You are judging Popperian ideas by standards which Popper rejected which is a mistake.

That is a recipe for disaster.

But it works in practice. The reason it doesn't turn into a disaster is people want to find the truth. They aren't stopped from making a mess of things by authoritative rules but by their own choices because they have some understanding of what will and won't work.

The authority based approach is a mistake in many ways. For example, authorities can themselves be mistaken and could impose disasters on people. And people don't always listen to authority. We don't need to try to force people to follow some authoritative theory to make them think properly, they need to understand the issues and do it voluntarily.

Personal preferences aren't evil, and imposing what you deem the best preference as a replacement is an anti-liberal mistake.

As I see it, Popperian reasoning is pretty much the way humans reason naturally

No. Since Aristotle, justificationism has dominated philosophy and governs the unconscious assumptions people make in debates. They do not think like Popperians or understand Popper's philosophy (except to the extent that some of their mental processes are capable of creating knowledge, and those have to be in line with the truth of the matter about what does create knowledge).

The argument for this is not short and simple, but I can give it. First I'd like to get clear what it means, and why we would be discussing it. Would you agree that if my statement here is correct then Popper is substantially right about epistemology? Would you concede? If not, what would you make of it?

Since I'm not familiar with the whole of Popper's position I'm noting going to accept it blindly. I'm also not even certain that he's incompatible with Bayesianism.

Anyway, that fact that no human has a starting point as badly flawed as anti-induction doe... (read more)

1[anonymous]15y

Step 1 is problematic also, as I explained in some of my comments to Tim Tyler. What should I gather data about? What kind of data? What measurements are important? How accurate? And so on.

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Bayesianism versus Critical Rationalism

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