Hard to Vary or Hardly Usable?
Dennis Hackethal started this discussion 2 months ago.
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With an account, you can revise, criticize, and comment on ideas, and submit new ideas.My critique of David Deutsch’s The Beginning of Infinity as a programmer. In short, his ‘hard to vary’ criterion at the core of his epistemology is fatally underspecified and impossible to apply.
Deutsch says that one should adopt explanations based on how hard they are to change without impacting their ability to explain what they claim to explain. The hardest-to-change explanation is the best and should be adopted. But he doesn’t say how to figure out which is hardest to change.
A decision-making method is a computational task. He says you haven’t understood a computational task if you can’t program it. He can’t program the steps for finding out how ‘hard to vary’ an explanation is, if only because those steps are underspecified. There are too many open questions.
So by his own yardstick, he hasn’t understood his epistemology.
You will find that and many more criticisms here: https://blog.dennishackethal.com/posts/hard-to-vary-or-hardly-usable
I think your challenge asks for the wrong kind of thing. Deutsch’s “hard to vary” is a guideline for criticizing explanations, not a step by step decision algorithm. In this paper he says scientific methodology does not prescribe exact procedures, and that “better” explanations are not always totally rankable in a clean, mechanical way. “Hard to vary” mainly means avoiding explanations that can be tweaked to fit anything, because then they explain nothing, so the lack of a universal scoring program does not refute the idea.
THE LOGIC OF EXPERIMENTAL TESTS, PARTICULARLY OF EVERETTIAN QUANTUM THEORY
https://www.constructortheory.org/portfolio/logic-experimental-tests/
From the paper (p. 3):
An explanation is better the more it is constrained by the explicanda and by other good explanations,5 but we shall not need precise criteria here; we shall only need the following: that an explanation is bad (or worse than a rival or variant explanation) to the extent that…
(i) it seems not to account for its explicanda; or
(ii) it seems to conflict with explanations that are otherwise good; or
(iii) it could easily be adapted to account for anything (so it explains nothing).
Hey Fitz, welcome to Veritula.
I realize that DD doesn’t think of it in strict, procedural terms, but I just don’t think that’s good enough, for several reasons. One is that it’s too vague, as I explain here. We don’t know how to actually do anything he says to do, beyond broad suggestions.
Deutsch’s “hard to vary” is a guideline for criticizing explanations, not a step by step decision algorithm.
But he says to use hard to vary as part of a decision-making algorithm. As quoted in my blog post:
“we should choose between [explanations] according to how good they are…: how hard to vary.”
I think the first question is whether HTV is a real concept (because if real, it is programmable, and via EC to arbitrary precision)
To understand if it’s real, we need to seek counterexamples/ counterarguments, not demand that a program can be written
What would such a program prove ? Not that HTV is real, but also not that we understand something about HTV.
That’s because Deutsch only says : no program = no understanding. That implies having a basic conception programmed can mean that you understand something. Take the season’s example, you could simulate that replacing Gods would not change the fact that they cry but that tears are not the same as rain etc. Granted, this would only be for 1 example, extending HTV to general examples would be needed. But with such basic program, for 1 example theory, we can’t conclude either that we do not understand anything about HTV.
Criticising HTV would anyway be the more important first step. Maybe examples of good theories with some ETV aspects (compared to rejected theories) in them could reveal some more.
Criticising HTV would anyway be the more important first step.
The linked blog post has several criticisms of HTV.
Do you mean "HTV is underspecified by Deutsch" ? But that is not a criticism ? It does not point to a mistake/ contradiction with HTV ?
It’s a criticism. Deutsch says to use HTV but never explains in sufficient detail how to do that.
How is that a criticism ? What mistake does it point out/ argue for ?
The mistake is insufficiency. If someone gives you a recipe for baking a cake but doesn’t specify ingredients or bake time, that’s a problem.
Isn't every theory infinitely underspecified ? Also, I would think that criteria for sufficiency must always be subjective ones (e.g. a working computerprogram cannot be itself a proof of meeting an some objective sufficiency criterium)? So I don't see how insufficiency points to a conflict of ideas/ contradiction
Isn't every theory infinitely underspecified ?
No. For example, the theory of addition is sufficiently specified: we have enough info to implement an algorithm of addition on a computer, then run it, test it, correct errors with it, and so on.
Yes. When you have program you can test a concept (incl. whether it is sufficiently defined to allow a program in the first place). But the other way around does not work: "If one does not have a program, then the concept is underspecified".
One way to program HTV could be to feed 2 explanations of the same phenomenon (in the form of text strings) to an LLM that is trained on seeking ETV patterns in text (things of the form "and then -all of a sudden- X happened ..." or "and Y (e.g. tears of a God) is kind of like Z (e.g. rain)" ) and seeking HTV patterns in text (e.g. Y happened because of X, with the LLM evaluating whether it is actual causation, whether if X did not happen, Y could not happen).And then the LLM could rank score the HTV-ness of each string (as a first approximation)
When you have program [sic] you can test a concept (incl. whether it is sufficiently defined to allow a program in the first place). But the other way around does not work: "If one does not have a program, then the concept is underspecified".
That isn’t what I said anyway. No disrespect but frankly I don’t think you know what you’re talking about.
I didn’t read the rest of your comment because you keep talking instead of coding. I’ll delete any further comments of yours that don’t contain code that at least tries to meet the bounty terms.
Also, I would think that criteria for sufficiency must always be subjective ones (e.g. a working computerprogram [sic] cannot be itself a proof of meeting an some objective sufficiency criterium)?
No, there are objective criteria.
Isn't every theory infinitely underspecified ?
This stance is presumably a version of the epistemological cynicism I identify here.
"HTV is underspecified by Deutsch"
That isn’t a quote. Don’t put things in quotation marks unless they are literal quotations or obviously scare quotes.
Criticising HTV would anyway be the more important first step. Maybe examples of good theories with some ETV aspects (compared to rejected theories) in them could reveal some more.
That could work, yeah. What other criticisms of HTV can you think of?
Deutsch’s stance in my own words:
The distinguishing characteristic between rationality and irrationality is that rationality is the search for good explanations. All progress comes from the search for good explanations. So the distinction between good vs bad explanations is epistemologically fundamental.
A good explanation is hard to vary “while still accounting for what it purports to account for.” (BoI chapter 1 glossary.) A bad explanation is easy to vary.
For example, the Persephone myth as an explanation of the seasons is easy to change without impacting its ability to explain the seasons. You could arbitrarily replace Persephone and other characters and the explanation would still ‘work’. The axis-tilt explanation of the earth, on the other hand, is hard to change without breaking it. You can’t just replace the axis with something else, say.
The quality of a theory is a matter of degrees. The harder it is to change a theory, the better that theory is. When deciding which explanation to adopt, we should “choose between [explanations] according to how good they are…: how hard to vary.” (BoI chapter 9; see similar remark in chapter 8.)
Deutsch leaves open how we find out how hard to vary an explanation is. We need more details. In some cases it’s obvious, but we need a general description for less-obvious cases.
Even if we allow creative user input, eg a score for the quality of an explanation, we run into all kinds of open questions, such as what upper and lower limits to use for the score, and unexpected behavior, such as criticisms pushing an explanation’s score beyond those limits.
Deutsch contradicts his yardstick for understanding a computational task. He says that you haven’t understood a computational task if you can’t program it. His method of decision-making based on finding good explanations is a computational task. He can’t program it, so he hasn’t understood it.
Isn’t this asking for a formalization of creativity, which is impossible?
No, it’s asking for a formalization of rational decision-making, which is a related but separate issue. Given a set of explanations (after they’ve already been created), what non-creative sorting algorithm do we use to find the best one?
Maybe Deutsch just means hard to vary as a heuristic, not as a full-fledged decision-making algorithm.
A heuristic or heuristic technique (problem solving, mental shortcut, rule of thumb) is any approach to problem solving that employs a pragmatic method that is not fully optimized, perfected, or rationalized, but is nevertheless "good enough" as an approximation or attribute substitution.
None of this means a heuristic couldn’t be programmed. On the contrary, heuristics sound easier to program than full-fledged, ‘proper’ algorithms.
I’d be happy to see some pseudo-code that uses workarounds/heuristics. That’d be a fine starting point.
@dirk-meulenbelt suggested in a space (at 21:30) that a bunch of epistemology is underspecified. There are many epistemological concepts (like criterion of democracy, falsifiability, etc.) that we don’t know enough about to express in code.
Yes, many ideas fail Deutsch’s yardstick. But so what? That doesn’t make things better.
Deutsch’s yardstick applies to computational tasks. It’s not meant for other things. It’s not clear to me that the criterion of democracy is a computational task.
Yes, the criterion for democracy is not a computational task, but an abstraction that constrains computational tasks. In the same way: the criterion for HTV is also not a computational task, it constrains the possible computational tasks that attempt to quantify HTV.
We understand computational tasks by being able to program them (as per Deutsch' criterion). But we understand criteria/ principles/ axioms/ theories ... (non computational tasks) in another way: by varying them and eliminating the variants that do not solve the problem the principle purported to solve.
For example:
a+b=b+a (in arithmetic) is a principle/ axiom that we understand by elimination of possible variants (a+b =/= a ... a+b =/=b ... etc)
but 3+5=5+3 is a specific transformation that should be understood via a computational task: adding 5 to 3 and then 3 to 5 and comparing both outcomes, via a program.
So my criticism is that the HTV criterion is not a computational task (but a principle, universal statement) and Deutsch's criterion of understanding (you need a program) only applies to computational tasks.
With principle/ universal statement/ theory, I mean for example: for all masses, there is a force proportional to the inverse square of their distances/ for all integers, addition is commutative/ for all species, their evolution is governed by variation and selection, for all interpretations of moral actions, they are moral relativism when ... applies to that interpretation/ ....
- Principles/ universal statements/ theories are not computable because they speak about sets of (possible) transformations (not 1 in particular which would be a computation) and they offer a constraining criterion to those transformations in the set.
- Whereas a computer program is an abstraction capable of causing 1 particular transformation (between sets of inputs and sets of outputs)
There may be a way to quantify HTV, and thus deal with specific evaluations of how HTV of one theory is higher than another. That would be a computational task. But that is different from the criterion for HTV (which is by definition not computable). And having no program for that computational task does not imply that the criterion for HTV is irrelevant or not usable, or even fluff.
Compare for example to the theory of evolution: the theory of "variation and selection" is the criterion for a set of allowable transformations (of species), but not having a specific program (e.g. for how a particular species can evolve in some particular niche) does not imply that the criterion is useless or fluff.
I think the usefulness of the HTV criterion becomes clear when you link it to Constructor Theory, then one can argue that HTV criterion adds more than criticisms alone can do. But that's a whole other story we could get into.
You criticized your own idea. Presumably that’s not what you meant to do.
HTV isn’t a principle even by your own definition. What on earth are you talking about man.
Even if HTV itself is not a computational task, the decision-making method Deutsch proposes is one, and it depends on HTV. But even if we sidestep that issue and outsource HTV completely to the user, we still run into all kinds of issues. This has all been addressed. No fancy talk about sets or constraints is going to change that.
You previously claimed you’re an engineer. I don’t think you are. You just pasted some code that was clearly written by AI and didn’t even compile, twice.
You talk about ‘sets’ and ‘constraints’ and ‘computations’ but I don’t think you understand any of them. No offense but I think those concepts are all distractions so you don’t need to actually address HTV. That’s why you need to use those big words.
Discussing with you is a waste of time. Again, no offense but I don’t think you’re qualified to weigh in on this discussion. Prove me wrong and submit working, handwritten code for HTV or Deutsch’s decision-making method. I’ll delete any further comments from you in this discussion that don’t contain working code. If you keep commenting anyway, I’ll lock your account.
Liberty said (at 1:38:39) hard to vary isn’t a method of decision-making. It’s a factor people take into account when they make decisions, but decision-making itself is a creative process.
I’m not saying hard to vary is a decision-making method. I’m saying it’s an integral part of Deutsch’s decision-making method. As I write in my article:
He argues that “we should choose between [explanations] according to how good they are…: how hard to vary.”
Liberty responded (1:39:46) that that quote is misleading because it makes it sound like hard to vary is the only criterion people use when making decisions, which can’t be true. There are other criteria, like “consistency with data”, “logical consistency”, “fitting in with existing theories”, etc.
The quote may be false, but I don’t see how it’s misleading. I’m not quoting Deutsch in isolation or cherry-picking information or anything like that.
Deutsch says to choose between explanations “according to how good they are” – note the plural.
What if I can only come up with one explanation? Can I just go with that one? What if it’s bad but still the best I could do? He leaves such questions open.
Deutsch says rationality means seeking good explanations, so without a step-by-step guide on how to seek good explanations, we cannot know when we are being irrational. That’s bad for error correction.
From my article:
[I]sn’t the difficulty of changing an explanation at least partly a property not of the explanation itself but of whoever is trying to change it? If I’m having difficulty changing it, maybe that’s because I lack imagination. Or maybe I’m just new to that field and an expert could easily change it. In which case the difficulty of changing an explanation is, again, not an objective property of that explanation but a subjective property of its critics. How could subjective properties be epistemologically fundamental?
fundamental
@zelalem-mekonnen suggested during a space (37:36) that hard to vary is just one mode of criticism.
Not according to Deutsch. He says hard to vary is epistemologically fundamental, that all progress is based on it. For example, he phrases testability in terms of hard to vary (BoI chapter 1):
When a formerly good explanation has been falsified by new observations, it is no longer a good explanation, because the problem has expanded to include those observations. Thus the standard scientific methodology of dropping theories when refuted by experiment is implied by the requirement for good explanations.
He also says that “good explanations [are] essential to science…” (thanks @tom-nassis for finding this quote). Recall that a good explanation is one that is hard to vary.
For Deutsch, hard to vary is the key mode of criticism, not just one of many.
From my article:
[D]epending on context, being hard to change can be a bad thing. For example, ‘tight coupling’ is a reason software can be hard to change, and it’s considered bad because it reduces maintainability.
From my article:
Isn’t the assignment of positive scores, of positive reasons to prefer one theory over another, a kind of justificationism? Deutsch criticizes justificationism throughout The Beginning of Infinity, but isn’t an endorsement of a theory as ‘good’ a kind of justification?
@lola-trimble suggested during a space that a theory is hard to vary if it’s not easy to vary. So the maximum score would be 0, not +1,000 or whatever. In which case ‘hard to vary’ isn’t an endorsement.
But calling a theory ‘good’ sounds like an endorsement. Deutsch also writes (BoI chapter 10) that a “superb” theory is “exceedingly hard to vary”. Ultimately we’d have to ask him, but for now, given the strength and positivity of those terms, I think it’s fair to conclude that he means ‘hard to vary’ as an endorsement.
Even so, if a criticism gets score -10, that will push the parent theory’s score above 0.
The criterion for HTV applied to 2 explanation is not justificationism I think. It allows to say explanation A is better than explanation B, which is equivalent to: explanation B is worse than explanation A. So it is a relative claim about an explanation, relative to another, not versus some absolute criterion of goodness. Similar to a crucial test (e.g. Eddington): we refute Newton's theory and keep Einsteins, that is not a claim about the goodness of Einsteins theory, that theory merely has survived, it has not gotten "goodness points". It could be refuted always later on by any better theory, in which case we would drop it too.
Similar to a crucial test …
But that’s exactly where HTV differs from Popper. Popper doesn’t give a theory points when it survives a crucial test. HTV does. From BoI chapter 1:
… testable explanations that have passed stringent tests become extremely good explanations …
That's because a good explanation for Deutsch is not an explanation with good points, but an explanation that is harder to vary compared to any other explanation. So again relative to other explanations.
The word "good" is indeed misleading in that sense, but he clearly qualifies it as performing better, relative to other explanations, on his HTV criterion, and not as: the explanation having scored high points.
with good points
I didn’t say the explanation doesn’t make good points, I said the explanation doesn’t get points.
So it is a relative claim about an explanation, relative to another, not versus some absolute criterion of goodness.
So what? I didn’t mention an absolute criterion. My original criticism already applies to both relative and absolute criteria of quality (what you call “goodness”).
Because relative criteria are fine to posit and not justificationist. We can propose criteria that claim that explanation A is better than explanation B without that being justificationism
From BoI chapter 1 glossary:
The misconception that knowledge can be genuine or reliable only if it is justified by some source or criterion.
That says nothing about absolute vs relative. Stop making up stuff.
@liberty-fitz-claridge says (#3885) it’d be implausible for HTV to be justificationist since that would contradict the rest of Deutsch’s anti-justificationist philosophy.
I don’t think that alone means my interpretation of HTV is implausible. We’re bound to find contradictions eventually. In a good book like BoI, they’re just rare, so when we do find them, they go against the bulk of the philosophy.
From my article:
[T]he assignment of positive values enables self-coercion: if I have a ‘good’ explanation worth 500 points, and a criticism worth only 100 points, Deutsch’s epistemology (presumably) says to adopt the explanation even though it has a pending criticism. After all, we’re still 400 in the black! But according to the epistemology of Taking Children Seriously, a parenting philosophy Deutsch cofounded before writing The Beginning of Infinity, acting on an idea that has pending criticisms is the definition of self-coercion. Such an act is irrational and incompatible with his view that rationality is fun in the sense that rationality means unanimous consent between explicit, inexplicit, unconscious, and any other type of idea in one’s mind.
In short, does the search for good explanations enable self-coercion and contradict TCS?
Our explanations do get better the more criticisms we address, but Deutsch has it backwards: the increasing quality of an explanation is the result of critical activity, not its means.
Choosing between explanations “according to how good they are” is vague. If I have three explanations, A, B, and C, and A is better than B is better than C, does that mean I adopt only A and reject both B and C? I assume so, but I don’t think Deutsch ever says anywhere.
The quoted statement is also compatible with adopting A with strong conviction, B with medium conviction (as a backup or something), and only slightly adopting C (if it’s still good, just not as good as the others) or rejecting C slightly (if it’s a little bad) or rejecting it very strongly (if it’s really bad).
Deutsch leaves open whether ‘difficulty to vary’ is a relative scale or an absolute one.
Do I need at least two explanations to know whether one is harder to vary than the other? Or can I tell, with only a single explanation, how hard it is to vary on its own?
Persephone vs axis tilt is low-hanging fruit. The reader finds it easy to disagree with the Persephone myth and easy to agree with the axis tilt, from cultural background alone. But that doesn’t mean there’s anything to hard to vary.
Deutsch should instead name some examples the reader would find easier to disagree with, and then walk them through why some explanations are harder to vary than others.
The ancient Greeks might have found the Persephone myth extremely hard to vary, eg due to cultural constraints. They wouldn’t have agreed that one could just swap out Persephone for someone else.