LessWrong has one of the strongest and most compelling presentations of a correspondence theory of truth on the internet, but as I said in A Pragmatic Epistemology, it has some deficiencies. This post delves into one example: its treatment of math and logic. First, though, I'll summarise the epistemology of...
For the past three thousand years epistemology has been about the truth, the whole truth, and nothing but the truth. Philosophers and scientists have continuously attempted to pinpoint the nature of truth, to find general logico-syntactic criteria for generating justified inferences, and to discover the true nature of reality. I...
All done.
Believing that a theory is true that says "true" is not a thing theories can be is obviously silly.
Oh okay. This is a two-part misunderstanding.
I'm not saying that theories can't be true, I'm just not talking about this truth thing in my meta-model. I'm perfectly a-okay with models of truth popping up wherever they might be handy, but I want to taboo the intuitive notion and refuse to explicate it. Instead I'll rely on other concepts to do much of the work we give to truth, and see what happens. And if there's work that they can't do, I want to evaluate whether it's important to include in the meta-model or... (read 375 more words →)
Many of them render considering them not true pointless, in the sense all my reasoning and senses are invalid if they don't hold so I might as well give up and save computing time by conditioning on them being true.
I call these sorts of models sticky, in the sense that they are pervasive in our perception and categorisation. Sitcky categories are the sort of thing that we have a hard time not taking literally. I haven't gone into any of this yet, of course, but I like it when comments anticipate ideas and continue trains of thought.
Maybe a short run-long run model would be good to illustrate this stickiness. In the... (read more)
That was a wonderful comment. I hope you don't mind if I focus on the last part in particular. If you'd rather I addressed more I can accommodate that, although most of that will be signalling agreement.
To assert P is equivalent to asserting "P is true" (the deflationary theory in reverse). That is still true if P is of the form "so and so works". Pragmatism is not orthogonal to, or transcendent of, truth. Pragmatists need to be concerned about what truly works.
I'll note a few things in reply to this:
Applying it to what problem? (If you mean the physics posts you linked to, I need more time to digest it fully)
No, not that comment, I mean the initial post. The problem is handling mathematical systems in an epistemology. A lot of epistemologies have a hard time with that because of ontological issues.
Nobody actually conceptualises science as being about deriving from thinking "pink is my favority color and it isn't" -> "causality doesn't work".
No, but many people hold the view that you can talk about valid statements as constraining ontological possibilities. This is including Eliezer of 2012. If you read the High Advance Epistemology posts on math, he does reason about the particular logical laws constraining how the physics of time and space work in our universe. And the view is very old, going back to before Aristotle, through Leibniz to the present.
If you call for a core change in epistemology it sounds like you want more than that. To me it's not clear what that more happens to be.
I'm going to have to do some strategic review on what exactly I'm not being clear about and what I need to say to make it clear.
In case you don't know the local LW definition of rationality is : "Behaving in a way that's likely to make you win."
Yes, I share that definition, but that's only the LW definition of instrumental rationality; epistemic rationality on the other hand is making your map more accurately reflect the territory. Part of what I want is to... (read more)
I think there's a bit of a misunderstanding going on here, though, because I am perfectly okay with people using classical logic if they like. Classical logic is a great way to model circuits, for example, and it provides some nice reasoning heuristics.There's nothing in my position that commits us to abandoning it entirely in favour of intuitionistic logic.
Intuitionistic logic is applicable to at least three real-world problems: formulating foundations for math, verifying programmes, and computerised theorem-proving. The last two in particular will have applications in everything from climate modeling to population genetics to quantum field theory.
As it happens, mathematician Andrej Bauer wrote a much better defence of doing physics with intuitionistic logic than I could have: http://math.andrej.com/2008/08/13/intuitionistic-mathematics-for-physics/
I've added an addendum. If reading that doesn't help, let me know and I'll summarise it for you in another way.
Intuitionistic logic can be interpreted as the logic of finite verification.
Truth in intuitionistic logic is just provability. If you assert A, it means you have a proof of A. If you assert ¬A then you have a proof that A implies a contradiction. If you assert A ⇒B then you can produce a proof of B from A. If you assert A ∨ B then you have a proof of at least one of A or B. Note that the law of excluded middle fails here because we aren't allowing sentences A ∨ ¬A where you have no proof of A or that A implies a contradiction.
In all cases, the... (read more)
LessWrong has one of the strongest and most compelling presentations of a correspondence theory of truth on the internet, but as I said in A Pragmatic Epistemology, it has some deficiencies. This post delves into one example: its treatment of math and logic. First, though, I'll summarise the epistemology of the sequences (especially as presented in High Advanced Epistemology 101 for Beginners).
Truth is the correspondence between beliefs and reality, between the map and the territory.[1] Reality is a causal fabric, a collection of variables ("stuff") that interact with each other.[2] True beliefs mirror reality in some way. If I believe that most maps skew the relative size of Ellesmere Island, it's true when I... (read 2341 more words →)
For the past three thousand years epistemology has been about the truth, the whole truth, and nothing but the truth. Philosophers and scientists have continuously attempted to pinpoint the nature of truth, to find general logico-syntactic criteria for generating justified inferences, and to discover the true nature of reality. I happen to think that truth is overrated. And by that I don't mean that I'm a stereotypical postmodernist, prepared to say that all views are on equal footing (because after all, who can really say what's true and what isn't?). Instead I mean that I don't even think that the truth is a useful or coherent concept when stretched to accommodate what... (read 1565 more words →)
I entered "Other: electic mixture" on the survey. On my Facebook profile, I elaborate this as "classical liberalism, Rawlsian liberalism, reactionary, left-libertarianism, conservatism, and techno-futurism." Ideologies are for picking apart, not buying wholesale. I gather a variety of them together and cut away the rotten parts like moldy cheese. What's left is something much more workable than the originals.