All of Sublation's Comments + Replies

Maybe the qualitative components of Bayes' theorem are, in some sense, pretty basic. If I think about how I would teach the basic qualitative concepts encoded by Bayes' theorem (which we both agree are useful), I can't think of a better way than through directly teaching Bayes' theorem. That is the sense in which I think Bayes' theorem offers a helpful precisification of these more qualitative concepts: it imposes a useful pedagogical structure into which we can neatly fit such principles.

You claim that the increased precision affo... (read more)

Could you say a bit more on why you think we should quantify the accuracy of credences with a strictly proper scoring rule, without reference to optimality proofs? I was personally confused about what principled reasons we had to think only strictly proper scoring rules were the only legitimate measures of accuracy, until I read Levinstein's paper offering a pragmatic vindication for such rules.

I enjoyed this post. I think the dialogue in particular nicely highlights how underdetermined the phrase 'becoming more Bayesian' is, and that we need more research on what optimal reasoning in more computationally realistic environments would look like.

However, I think there are other (not explicitly stated) ways I think Bayesianism is helpful for actual human reasoners. I'll list two:

  • I think the ingredients you get from Bayes' theorem offer a helpful way of making more precise what updating should look like. Almost everyone will agr
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2Richard_Ngo
Thanks for the comment :) I agree with your second point, and alluded to it by having Bob mention the importance of considering degrees of belief as probabilities. Perhaps I should make this point more strongly, but at the same time, it's definitely not something that's unique to bayesianism, and you could advocate for it on its own merits. I guess the historical context is relevant: were the original people who advocated for thinking of degrees of belief in probabilistic terms bayesians? I don't know enough to answer that question. I disagree with your first point. I think the basic framework - what did I use to believe, what have I learned, how have I changed my mind - is exactly that: basic. It doesn't need to be justified in terms of Bayes, it was around far before that. Insofar as Bayes makes it more precise, it also makes it more inapplicable, because people adopt the parts of "precise Bayesian updates" that they agree with, but not all the others which I mention in the dialogue.

This was my reconstruction of Caspar's argument, which may be wrong. But I took the argument to be that we should promote consequentialism in the world as we find it now, where Omega (fingers crossed!) isn't going to tell me claims of this sort, and people do not, in general, explicitly optimise for things we greatly disvalue. In this world, if people are more consequentialist, then there is a greater potential for positive-sum trades with other agents in the multiverse. As agents, in this world, have some overlap with our values, we should encourage consequentialism, as consequentialist agents we can causally interact with will get more of what they want, and so we get more of what we want.

I agree with you that choosing the appropriate set of actions is a non-trivial task, and I've said nothing here about how Kantians would choose an appropriate class of actions.

I am unclear on the point of your gang examples. You point out that the ideal maxim changes depending on features of the world. The Kantian claim, as I understand it, says that we should implement a particular decision-theoretic strategy, by focusing on maxims rather than acts. This a distinctively normative claim. The fact that, as we gain more information, the maxims might bec... (read more)

On my current understanding of this post, I think I have a criticism. But I'm not sure if I properly understand the post, so tell me if I'm wrong in my following summary. I take the post to be saying something like the following:

'Suppose, in fact, I take the action A. Instead of talking about logical counterfactuals, we should talk about policy-dependent source code. If we do this, then we can see that initial talk about logical counterfactuals encoded an error. The error is not understanding the following claim: when asking what would have
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4jessicata
The summary is correct. Indeed, it is underdetermined what the alternative source code is. Sometimes it doesn't matter (this is the case in most decision problems), and sometimes there is a family of programs that can be assumed. But this still presents theoretical problems. The motivation is to be a nonrealist about logical counterfactuals while being a realist about some counterfactuals.

Thanks, that's helpful. Edited.