Hard to Vary or Hardly Usable?
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With an account, you can revise, criticize, and comment on 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:
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).
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.”