Reflections on Rat Fest ’25

I think of it in terms of error correction: all fields where progress is possible allow us to identify and correct errors.

Empirical fields use facts. In empirical fields, error identification involves finding a discrepancy between theories and observation.

I’d consider aesthetics and economics at least partly empirical since you can make testable predictions. You can test an economic policy, for example, and see whether its predictions match (correspond to) outcomes. In music, things can sound unpleasant.

No worries :-). Yeah, this is the part that confuses me about correspondence:

Which fields (apart from science) have "facts", and which consist merely of useful/adapted knowledge?

For instance, are there musical facts, economic facts, aesthetic facts, etc?

Sorry for the late reply. I don’t know. I don’t think the aim of math is correspondence to physical facts like in science. But maybe it’s correspondence to mathematical facts.

I think so, yeah. But it’s been years since I watched DD’s talk on propositions. I’d have to re-watch it to give you a more competent answer.

Between two abstractions (ambiguous statements made by us, and perfectly precise propositions).

…you only think we need it to explain progress in science.

No, I think progress in science is explained by error correction. The aim of science is correspondence. There’s a difference between aims and means.

Are you asking if there can be correspondence between two abstractions? Or between a physical object and an abstraction?

Thanks. Do you think there's correspondence for abstractions as well (such as mathematics, as DD seems to suggest)? As I understood, you only think we need it to explain progress in science.

See here. Lucas had asked:

Can you say more about why we need correspondence to make sense of the concept of self-similarity? I don't see why. And it seems to me that self-similarity is all we need to make sense of the universality of computation.

My response below. For others reading this, Erik has also since started a dedicated discussion on the topic of correspondence: https://veritula.com/discussions/is-correspondence-true-in-cr

The FoR glossary entry on self-similarity from chapter 4 reads:

self-similarity Some parts of physical reality (such as symbols, pictures or human thoughts) resemble other parts. The resemblance may be concrete, as when the images in a planetarium resemble the night sky; more importantly, it may be abstract, as when a statement in quantum theory printed in a book correctly explains an aspect of the structure of the multiverse.

The way I read that, it means the images in the planetarium correspond to the night sky. Otherwise we wouldn’t consider them similar.

From chapter 6, on the universality of computation and how “various parts of reality can resemble one another”:

The set of all behaviours and responses of that one object exactly mirrors the set of all behaviours and responses of all other physically possible objects and processes.

That means there is one-to-one correspondence between the behaviors and responses of the first object and those of all the other objects. This is basically another way to describe the self-similarity property of the universe.

From chapter 10, in the context of mathematics (italics mine):

… the physical behaviour of the symbols corresponds to the behaviour of the abstractions they denote.

(The same is true of the physical parts of a Turing machine harnessing the self-similarity property of the universe to correspond to other physical objects.)

From chapter 14, in the context of the creation of scientific knowledge (which, AFAIK, DD views as increasing correspondence):

The creation of useful knowledge by science … must be understood as the emergence of the self-similarity that is mandated by a principle of physics, the Turing principle.

It’s been ages since I read FoR so I’m relying on word searches in the ebook but it’s full of these links between self-similarity and correspondence.

Fixed as of v5.

… Rat Festers cite Popper and Deutsch as if they are infallible.

Shouldn’t it be ‘as if they were infallible’?

Fixed as of 2025-10-08.

Aaron Stupple, author of a parenting guide called The Sovereign Child, talks about how to raise your kids without making them do things they don’t want to do. I tell Stupple I wish I’d read his book when my son and daughter were young, and I mean it, Stupple strikes me as wise. But it bothers me that Stupple was inspired by Deutsch, who has no kids.

https://blog.dennishackethal.com/posts/but-you-re-not-a-parent

Well, Tom wouldn’t do it anyway because he’s British.

Contrary to Deutsch, they do not believe that problems are fully soluble; contrary to Popper, they do not believe that we can ever find the truth in any matter.

Isn’t Deutsch a cynic, too? Look for quotes…

I didn’t have a counter to #2104, fixed it as of v2.

Ayn Rand’s book The Romantic Manifesto has 114 matches for the string ‘esthetic’ and no matches for the string ‘aesthetic’. Rand was a serious philosopher who did extensive work on art and (a)esthetics.

There’s also her talk ‘The Esthetic Vacuum of Our Age’, though it may have been the Ayn Rand Institute that chose that spelling.

Justin says no philosopher would drop the ‘a’, including Tom Hyde, whom Justin calls a serious British philosopher.

Justin says the term ‘esthetician’ “ruined that”.

My macOS Dictionary app says “aesthetics … (also esthetics)”.

Isn’t ‘esthetics’ just the American spelling and ‘aesthetics’ is British?

From https://nocoaaa.com/blog/aesthetics-vs-esthetics:

Many individuals are confused about the distinction between Aesthetics and Esthetics. The only difference between these two terms is that they are spelled differently. People in European and Commonwealth countries use the term aesthetics. Americans, on the other hand, commonly use the term esthetic.

Justin says it’s better to spell it ‘aesthetics’ than ‘esthetics’.

Can you be skeptical without falling into self-contradiction, like Popper and Kuhn?

Popper was not a skeptic. Skepticism, as an epistemology, says there can be no genuine knowledge. Popper opposed skepticisism.