[dotsam]

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 Furthermore if we expect, with Popper, that all our best theories of fundamental physics are going to be superseded eventually, and we therefore believe their negations, it is still those false theories, not their true negations, that constitute all our deepest knowledge of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...

[marcosdumay]

Any refutation that depends on the fundamental unknownability of the Universe rules trivially applies to every single philosophy of science.

Science must work despite it, or you don't have science.

And any other singularity you get from assuming the odds of a hypothesis is infinitely smaller than the odds of it being false is unrealistic. You shouldn't assume that.

[badRNG]

> we expect, with Popper, that all our best theories of fundamental physics are going to be superseded eventually

This inductive case against scientific knowledge should only serve to decrease our second-order credence in the proposition that we have assigned the highest credence to the scientific hypotheses that most closely correspond with reality. It does nothing to change the fact that, conditional on evidence we currently have, we may very well have correctly proportioned credence.

[adrianN]

„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]

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.

[hammock]

Love this. So clearly written. The truest thing we know is how much we don’t know

[kerkeslager]

Bullshit like this is exactly why I think scientists are better philosophers than philosophers are. The text you've quoted, is, frankly, not the writings of an intelligent person.

The reason I'm being very blunt about this, is because bullshit like this is actively harmful. Science is fucking important. Science is what resulted in the technology you're using to read this. Science is, with non-negligible probability, the basis of medicine that prevented you from dying before the age of 5 to be able to read this. When philosophers posit that they can inspect the their own navels and find deep truths about the world, they are undermining one of the fundamental pillars of society that holds up so much of the positive changes humans have been able to make.

We need to call this what it is--nonsense and misinformation--and stop amplifying its signal.

> 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.

Of course "the sun is not powered by nuclear fusion" IS an explanation, it's just not an explanation of a phenomenon we observe, which is why most scientists don't believe "the sun is not powered by nuclear fusion". If we observed something about the sun that was not consistent with the hypothesis that it is powered by nuclear fusion, "the sun is not powered by nuclear fusion" would indeed be an explanation of what we were observing.

This is all sidestepping the absurdity that Deutsch doesn't seem to understand that "none at all" has a mathematical representation, 0, meaning that if p = 1 - q = 0, then q = 1. This is not difficult math here, folks.

> 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.

Uh sure, which is why nobody with a brain takes the conjunction of those two things. This isn't a criticism of Bayesian philosophy of science, it's a straw man argument.

> 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.

Deutsch apparently doesn't know what an approximation is, and instead thinks of correct/incorrect as a binary. Relevant https://hermiene.net/essays-trans/relativity_of_wrong.html

[n4r9]

Deutsch is primarily a physicist, not a philosopher. I'm not a fan of his philosophical takes either but he is not as stupid as you infer. He invented the Deutsch-Josza algorithm along with Richard Josza, the first example of absolute quantum speedup.

[BlandDuck]

I agree entirely. As a professional scientist who routinely uses Bayesian methods to solve complex computational and statistical problems, with actual real world applications, I cannot stress enough how irrelevant such philosophical musings about the foundations of Bayesian Statistics are for getting actual science work done.

[parodysbird]

I don't think you know what you're responding to, but in any case, regarding Deutsch, he "laid the foundations of the quantum theory of computation, and subsequently made or participated in many of the most important advances in the field, including the discovery of the first quantum algorithms, the theory of quantum logic gates and quantum computational networks, the first quantum error-correction scheme, and several fundamental quantum universality results."

[PunchTornado]

you should really try to think and understand what the other is saying, because your text doesn't show that you've put the effort.

[cubefox]

> Bullshit like this is exactly why I think scientists are better philosophers than philosophers are. The text you've quoted, is, frankly, not the writings of an intelligent person.

Which instantly refutes your position, because the alleged "bullshit" he quoted was written by a scientist, David Deutsch, not a by philosopher. Meanwhile, the defenders of "Bayesian philosophy of science" and (largely synonymous) "Bayesian epistemology" are mainly philosophers.

Am I correct in assuming you will now account for the above mistake and change your opinion to "Bullshit like this is exactly why I think philosophers are better philosophers than scientists are"?