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Going to leave this here: https://plato.stanford.edu/entries/popper/#GrowHumaKnow https://plato.stanford.edu/entries/popper/#GrowHumaKnow

Mizza 2y ago
Thank you for beating me to it. Astounding how those LessWrong dorks were able to revive the corpse of this dead end of epistemology after it was so thoroughly destroyed by Popper. And to what benefit.. sex crimes, massive financial fraud, murder cults and a far right government? Here's a fun one https://sci-hub.3800808.com/10.1038/302687a0 https://sci-hub.3800808.com/10.1038/302687a0
- llm_trw 2y ago
  I never thought I'd see a misunderstanding of what "implies" means in science versus in logic be the fundamental mistake made in a paper on logic for science. Here's the truth table for implies (if) in logic. | A | B | If A then B | |---+---+-------------| | T | T | T | | T | F | F | | F | T | T | | F | F | T | Show this to anyone in the sciences who hasn't done logic and you'll instantly get the objections "But hang on, the two rows at the bottom don't fit!". This is where you need to add temporal logic so that the scientific understanding of A casually implies B can be represented in logic. In short the paper does nothing of the sort of what it says it does because it fundamentally uses the wrong tool for the job.
  - Mizza 2y ago
    But those two rows are vacuous truths, which Popper obviously doesn't care about in context as they're not falsifiable.
    - llm_trw 2y ago
      The whole paper depends on the factorization: B = (A or B) and (if A then B) In the following table we have the other three operations which give different truth values to what you call the vacuous case. If "if" is replaced by "x" or "y" in the following table than that factorization does not work, "z" still does work but I'd be hard pressed to find anyone who thinks it represents causal implication better than "if" or "x". | A | B | x A B | y A B | z A B | If A then B | |---+---+-------+-------+-------+-------------| | T | T | T | T | T | T | | T | F | F | F | F | F | | F | T | F | F | T | T | | F | F | F | T | F | T | I'm not using the common names for the operations to not bias people. Or to put it another way: No one outside a logic course seriously thinks that A implies B means the same thing as not A or B.
      - JohnKemeny 2y ago
        It’s a common pattern in programming too. Consider the rule: If a user has write access, then they must be an admin. If you write a function to enforce this, you’ll naturally follow logical implication—checking if the user has write access and raising an error if they aren’t an admin, while doing nothing if they don’t have write access.
        llm_trw 2y ago
        The issue is that in a scientific experiment you can only change the state of A. If for whatever reason B is stuck to T in all cases no one will think that A implies B, they will think that B is independent of A. Yet that would still fit with a world in which A logically implies B. You would need B to be dependent on a third variable which you're not controlling in the experiment that allows the value of B to change T or F outside your control. Any good experimentalist will tell you to fix your broken experiment if that kept happening. It's only when you have no control over the variables and you collect statistics that the view in the paper makes sense. That's the difference between experimental and observational science. And the philosophy of science is decades to centuries away from understanding that in any meaningful way.
        deleted 2y ago
        [deleted]
- kerkeslager 2y ago
  Popper did not do anything of the sort. First, I think Popper did not fundamentally disagree with the Bayesian approach: ultimately his critique of Bayesianism is a small adjustment to Bayesianism. When presented with a set of competing hypotheses { h_0, h_1, h_2... }, Bayesianism says that we assign a probability to each, whereas Popper points out that experiments and observation never really actually add credence to a hypothesis, they rather only decrease the probability of a hypothesis. In theory, decreasing the probability of hypothesis h_0 does not increase the probability of hypothesis h_1, because the set of hypotheses is infinite--that is to say for any n there is always a potential h_{n+1} which has not been thought of by scientists. We know that the sum of the probabilities of hypotheses must be 1, but since the set of hypotheses is an infinite set, decreasing the probability of h_0 does not necessarily increase the probability of h_1, because the probability of any h_n in the set could be increasing. I think Popper is right in theory, but in practice, I think this is less important than philosophers think it is. Pragmatically, we can treat the set of hypotheses as finite, operating only on the hypotheses humans have... hypothesized. We have no way to operate on hypotheses nobody has thought of, so we just operate on the set of hypotheses we have thought of. Since the sum of this set of probabilities must be 1, decreasing the probability of one hypothesis does increase the probability of all the other hypotheses in the set. Where Popper's critique becomes important is if we keep decreasing the probabilities of all the hypotheses in the set--this indicates that the hypothesis which is true is not in the set (i.e. nobody has come up with the correct hypothesis to test). This indicates a need for new hypotheses. But in a lot of cases, experimentation keeps decreasing the probability of all the hypotheses except one in the finite set of hypotheses humans have thought of, while numerous attempts to decrease the probability of that one hypothesis fail. While Popper would say this does not increase the probability of that one hypothesis, operating as if it does increase the probability of that hypothesis seems to work. We've been able to go to the moon, eradicate smallpox, and build intelligent-seeming machines, all based on hypotheses that we "increased the probability of" in this way, even though increasing the probability of a hypothesis is theoretically impossible. This all goes back to philosophers' favorite navelgazing claim: that nothing is knowable. Ultimately, I think this is a dishonest argument which even philosophers don't believe. I've offered to punch many a philosopher in the face: after all, it's not knowable that it's going to hurt. But strangely, philosophers who claim to believe that nothing is knowable DO seem to know that will hurt, and none have taken me up on my offer.* * Unlike the philosophers, I do believe in (probablistic) knowability, and I'm highly confident that punching them in the face would hurt them, so if anyone actually takes me up on this offer, I (probably) won't punch them. So far, no one has called my bluff.
dotsam 2y ago
Relatedly, David Deutsch's "Simple refutation of the ‘Bayesian’ philosophy of science" > By ‘Bayesian’ philosophy of science I mean the position that (1) the objective of science is, or should be, to increase our ‘credence’ for true theories, and that (2) the credences held by a rational thinker obey the probability calculus. However, if T is an explanatory theory (e.g. ‘the sun is powered by nuclear fusion’), then its negation ~T (‘the sun is not powered by nuclear fusion’) is not an explanation at all. Therefore, suppose (implausibly, for the sake of argument) that one could quantify ‘the property that science strives to maximise’. If T had an amount q of that, then ~T would have none at all, not 1-q as the probability calculus would require if q were a probability. > Also, the conjunction (T₁ & T₂) of two mutually inconsistent explanatory theories T₁ and T₂ (such as quantum theory and relativity) is provably false, and therefore has zero probability. Yet it embodies some understanding of the world and is definitely better than nothing. > Furthermore if we expect, with Popper, that all our best theories of fundamental physics are going to be superseded eventually, and we therefore believe their negations, it is still those false theories, not their true negations, that constitute all our deepest knowledge of physics. > What science really seeks to ‘maximise’ (or rather, create) is explanatory power. https://www.daviddeutsch.org.uk/2014/08/simple-refutation-of-the-bayesian-philosophy-of-science/ https://www.daviddeutsch.org.uk/2014/08/simple-refutation-of...
- adrianN 2y ago
  „The sun is not powered by fusion“ actually contains a little information as to the inner workings of the star, so I’m a bit confused by the argument.
  - ThomPete 2y ago
    Not from a non-bayesian perspective. It's what Deutsch would call a "bad explanation" i.e. it's easy to vary and thus doesn't tell us about how the sun is powered.
    - kerkeslager 2y ago
      It's a bad explanation because the sun (probably) IS powered by nuclear fusion. Deutsch is confused by this situation because he doesn't have the scientific background to understand the usefulness of negations of hypotheses. Historically, for example, a lot of people believed the sun revolved around the earth. If we treat this as T, then ~T is "the sun does not revolve around the earth". ~T certainly lacks details, but to say it's a "bad explanation" is rather silly. Obviously it's an incomplete explanation, which is why Galileo presented a full explanation ("the earth revolves around the sun") rather than just saying, "the sun does not revolve around the earth". But in fact, "the sun does not revolve around the earth" was the part that was controversial because it was the bad explanation being presented by the church (who happened to be closer to philosophers than scientists). Basically, Deutsch is just making a straw man argument. In Deutsch's mind, the fact that "the sun does not revolve around the earth" is an incomplete theory of heliocentrism is somehow a refutation of all science, when in fact that's simply not the sort of hypothesis scientists even explore typically.

Mizza 2y ago

Thank you for beating me to it. Astounding how those LessWrong dorks were able to revive the corpse of this dead end of epistemology after it was so thoroughly destroyed by Popper. And to what benefit.. sex crimes, massive financial fraud, murder cults and a far right government? Here's a fun one https://sci-hub.3800808.com/10.1038/302687a0 https://sci-hub.3800808.com/10.1038/302687a0

llm_trw 2y ago
I never thought I'd see a misunderstanding of what "implies" means in science versus in logic be the fundamental mistake made in a paper on logic for science. Here's the truth table for implies (if) in logic. | A | B | If A then B | |---+---+-------------| | T | T | T | | T | F | F | | F | T | T | | F | F | T | Show this to anyone in the sciences who hasn't done logic and you'll instantly get the objections "But hang on, the two rows at the bottom don't fit!". This is where you need to add temporal logic so that the scientific understanding of A casually implies B can be represented in logic. In short the paper does nothing of the sort of what it says it does because it fundamentally uses the wrong tool for the job.
- Mizza 2y ago
  But those two rows are vacuous truths, which Popper obviously doesn't care about in context as they're not falsifiable.
  - llm_trw 2y ago
    The whole paper depends on the factorization: B = (A or B) and (if A then B) In the following table we have the other three operations which give different truth values to what you call the vacuous case. If "if" is replaced by "x" or "y" in the following table than that factorization does not work, "z" still does work but I'd be hard pressed to find anyone who thinks it represents causal implication better than "if" or "x". | A | B | x A B | y A B | z A B | If A then B | |---+---+-------+-------+-------+-------------| | T | T | T | T | T | T | | T | F | F | F | F | F | | F | T | F | F | T | T | | F | F | F | T | F | T | I'm not using the common names for the operations to not bias people. Or to put it another way: No one outside a logic course seriously thinks that A implies B means the same thing as not A or B.
    - JohnKemeny 2y ago
      It’s a common pattern in programming too. Consider the rule: If a user has write access, then they must be an admin. If you write a function to enforce this, you’ll naturally follow logical implication—checking if the user has write access and raising an error if they aren’t an admin, while doing nothing if they don’t have write access.
      - llm_trw 2y ago
        The issue is that in a scientific experiment you can only change the state of A. If for whatever reason B is stuck to T in all cases no one will think that A implies B, they will think that B is independent of A. Yet that would still fit with a world in which A logically implies B. You would need B to be dependent on a third variable which you're not controlling in the experiment that allows the value of B to change T or F outside your control. Any good experimentalist will tell you to fix your broken experiment if that kept happening. It's only when you have no control over the variables and you collect statistics that the view in the paper makes sense. That's the difference between experimental and observational science. And the philosophy of science is decades to centuries away from understanding that in any meaningful way.
      - deleted 2y ago
        [deleted]
kerkeslager 2y ago
Popper did not do anything of the sort. First, I think Popper did not fundamentally disagree with the Bayesian approach: ultimately his critique of Bayesianism is a small adjustment to Bayesianism. When presented with a set of competing hypotheses { h_0, h_1, h_2... }, Bayesianism says that we assign a probability to each, whereas Popper points out that experiments and observation never really actually add credence to a hypothesis, they rather only decrease the probability of a hypothesis. In theory, decreasing the probability of hypothesis h_0 does not increase the probability of hypothesis h_1, because the set of hypotheses is infinite--that is to say for any n there is always a potential h_{n+1} which has not been thought of by scientists. We know that the sum of the probabilities of hypotheses must be 1, but since the set of hypotheses is an infinite set, decreasing the probability of h_0 does not necessarily increase the probability of h_1, because the probability of any h_n in the set could be increasing. I think Popper is right in theory, but in practice, I think this is less important than philosophers think it is. Pragmatically, we can treat the set of hypotheses as finite, operating only on the hypotheses humans have... hypothesized. We have no way to operate on hypotheses nobody has thought of, so we just operate on the set of hypotheses we have thought of. Since the sum of this set of probabilities must be 1, decreasing the probability of one hypothesis does increase the probability of all the other hypotheses in the set. Where Popper's critique becomes important is if we keep decreasing the probabilities of all the hypotheses in the set--this indicates that the hypothesis which is true is not in the set (i.e. nobody has come up with the correct hypothesis to test). This indicates a need for new hypotheses. But in a lot of cases, experimentation keeps decreasing the probability of all the hypotheses except one in the finite set of hypotheses humans have thought of, while numerous attempts to decrease the probability of that one hypothesis fail. While Popper would say this does not increase the probability of that one hypothesis, operating as if it does increase the probability of that hypothesis seems to work. We've been able to go to the moon, eradicate smallpox, and build intelligent-seeming machines, all based on hypotheses that we "increased the probability of" in this way, even though increasing the probability of a hypothesis is theoretically impossible. This all goes back to philosophers' favorite navelgazing claim: that nothing is knowable. Ultimately, I think this is a dishonest argument which even philosophers don't believe. I've offered to punch many a philosopher in the face: after all, it's not knowable that it's going to hurt. But strangely, philosophers who claim to believe that nothing is knowable DO seem to know that will hurt, and none have taken me up on my offer.* * Unlike the philosophers, I do believe in (probablistic) knowability, and I'm highly confident that punching them in the face would hurt them, so if anyone actually takes me up on this offer, I (probably) won't punch them. So far, no one has called my bluff.

dotsam 2y ago

Relatedly, David Deutsch's "Simple refutation of the ‘Bayesian’ philosophy of science" > By ‘Bayesian’ philosophy of science I mean the position that (1) the objective of science is, or should be, to increase our ‘credence’ for true theories, and that (2) the credences held by a rational thinker obey the probability calculus. However, if T is an explanatory theory (e.g. ‘the sun is powered by nuclear fusion’), then its negation ~T (‘the sun is not powered by nuclear fusion’) is not an explanation at all. Therefore, suppose (implausibly, for the sake of argument) that one could quantify ‘the property that science strives to maximise’. If T had an amount q of that, then ~T would have none at all, not 1-q as the probability calculus would require if q were a probability. > Also, the conjunction (T₁ & T₂) of two mutually inconsistent explanatory theories T₁ and T₂ (such as quantum theory and relativity) is provably false, and therefore has zero probability. Yet it embodies some understanding of the world and is definitely better than nothing. > Furthermore if we expect, with Popper, that all our best theories of fundamental physics are going to be superseded eventually, and we therefore believe their negations, it is still those false theories, not their true negations, that constitute all our deepest knowledge of physics. > What science really seeks to ‘maximise’ (or rather, create) is explanatory power. https://www.daviddeutsch.org.uk/2014/08/simple-refutation-of-the-bayesian-philosophy-of-science/ https://www.daviddeutsch.org.uk/2014/08/simple-refutation-of...

adrianN 2y ago
„The sun is not powered by fusion“ actually contains a little information as to the inner workings of the star, so I’m a bit confused by the argument.
- ThomPete 2y ago
  Not from a non-bayesian perspective. It's what Deutsch would call a "bad explanation" i.e. it's easy to vary and thus doesn't tell us about how the sun is powered.
  - kerkeslager 2y ago
    It's a bad explanation because the sun (probably) IS powered by nuclear fusion. Deutsch is confused by this situation because he doesn't have the scientific background to understand the usefulness of negations of hypotheses. Historically, for example, a lot of people believed the sun revolved around the earth. If we treat this as T, then ~T is "the sun does not revolve around the earth". ~T certainly lacks details, but to say it's a "bad explanation" is rather silly. Obviously it's an incomplete explanation, which is why Galileo presented a full explanation ("the earth revolves around the sun") rather than just saying, "the sun does not revolve around the earth". But in fact, "the sun does not revolve around the earth" was the part that was controversial because it was the bad explanation being presented by the church (who happened to be closer to philosophers than scientists). Basically, Deutsch is just making a straw man argument. In Deutsch's mind, the fact that "the sun does not revolve around the earth" is an incomplete theory of heliocentrism is somehow a refutation of all science, when in fact that's simply not the sort of hypothesis scientists even explore typically.