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.

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 doesn't make Bayesianism invalid. It may well be that we are just very badly flawed, and can only get out of those flaws by taking the mathematically best approach to truth. This is Bayesianism, it has been proven in more than one way.

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.

This is exactly we we need induction. It is usually possible to stick any future onto any past and get a consistent history, induction tells us that if we want a probable history we need to make the future and the past resemble each other.

The reason it doesn't turn into a disaster is people want to find the truth.

People certainly say that. Most of them even believe it on a conscious level, but there in your average discussion there is a huge amount of other stuff going on, from signalling tribal loyalty to rationalising away unpleasant conclusions. You will not wander down the correct path by chance, you must use a map and navigate.

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.

I have no further interest in talking with you if you resort to straw men like this. I am not proposing we set up a dictatorship and kill all non-Bayesians, nor am I advocating censorship of views opposed the correct Bayesian conclusion.

All I am saying is your mind was not designed to do philosophical reasoning. It was designed to chase antelope across the savannah, lob a spear in them, drag them back home to the tribe, and come up with an eloquent explanation for why you deserve a bigger share of the meat (this last bit got the lion's share of the processing power).

Your brain is not well suited to abstract reasoning, it is a fortunate coincidence that you are capable of it at all. Hopefully, you are lucky enough to have a starting point which is not irreversibly flawed, and you may be able to self improve, but this should be in the direction of realising that you run on corrupt hardware, distrusting your own thoughts, and forcing them to follow rigorous rules. Which rules? The ones that have been mathematically proven to be the best seem like a good starting point.

(The above is not intended as a personal attack, it is equally true of everyone)

Anyway, that fact that no human has a starting point as badly flawed as anti-induction doesn't make Bayesianism invalid.

I did not say it makes Bayesianism invalid. I said it doesn't make Popperism invalid or require epistemological pessimism. You were making myth of the framework arguments against Popper's view. My comments on those were not intended to refute Bayesianism itself.

This is exactly we we need induction. It is usually possible to stick any future onto any past and get a consistent history, induction tells us that if we want a probable hist

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