So I'm not going to put forth counter-arguments to show that the things you're putting forth are wrong, because they're mostly not. — Pfhorrest
the correct formulation for confirmationism is "if Q then P", — Janus
Where e is some evidence, h is some hypothesis, k is some set of background assumptions, and ⊨ is a symbol for entailment, i.e. necessary implication.e HD-confirms h relative to k if and only if h ∧ k ⊨ e and k ⊭ e; — SEP
e confirms h relative to k if and only if e disconfirms ¬h relative to k. — SEP
but you stopped short of admitting that your identification of confirmationist thought with the invalid syllogism was incorrect — Janus
Do you really believe there have been any philosophically significant confirmationists stupid enough to base their whole system of thought on an invalid syllogism, though? — Janus
Originally, Glymour presented his sophisticated neo-Hempelian approach in stark contrast with the competing traditional view of so-called hypothetico-deductivism (HD).
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For one thing, the very idea of hypothetico-deductivism has often been said to stem from the origins of Western science.
Conversely "Some swans are purple" can never be definitively falsified, but could be definitively verified. — Janus
universal statements cannot be definitively verified for obvious reasons; we can never observe every case, or even if we have observed every case, know that we have. So universal statements can only be falsified. Apparently some of the logical positivists were not happy with this because according to their own criterion universal statements would have to be thought to be meaningless. It's surprising that something so obviously wrong would be clung to by highly intelligent thinkers. — Janus
In short, your instinct was right, they weren't that stupid. The confusion comes from a naïve treatment of our beliefs as if they were a half-dozen independent logical correlations rather than a complex network of hundreds of thousands of interconnected implications. — Isaac
I never said inductive thought generally was to be dispensed with entirely. I've repeatedly said induction is a fine way to come up with beliefs in the first place. — Pfhorrest
So in the strictest sense, you haven't confirmed that there exists at least that one purple swan, even though in a colloquial sense we can often be sure enough for practical purposes. — Pfhorrest
But it's very unlikely that you're both probably right about all swans being white, and probably really seeing a purple swan, so you're probably wrong about at least one of those things. — Pfhorrest
I had thought that you said early on in this thread and repeatedly thereafter that it doesn't matter what we believe (that is falsifiable) as long as it hasn't been falsified. — Janus
Yes, but that "strictest sense" as I already said applies to everything; it is merely the fact that there is not any absolute certainty; no deductive strength proof of anything, when it comes to empirical matters. But that is really a useless wasteland of weeds we don't need to get into.
You could say the same about black swans; that it could never be absolutely proven that they are in fact swans. — Janus
It's in that sense that although we can never be sure any particular set of beliefs is the correct, we can be sure that some particular set of beliefs is an incorrect one, if e.g. that particular set of beliefs says both that all swans are white and that the thing we're seeing right now is a purple swan. We can't be sure which of those (or which part of which of them) is incorrect, but we can be sure that the world definitely isn't exactly like that, it's different than we thought in some way or another. — Pfhorrest
Not the belief that I haven't seen any purple swans (I'm presuming I was deceived). — Isaac
Other way around: you change the beliefs which initially lead you to construe your experience as genuinely seeing a real purple swan, if you instead conclude that you must have been deceived. — Pfhorrest
This still accords with Bayesian reasoning, because you could reason along the same lines, but probabilistically instead of in those absolute statements. If the thing you're observing is very likely to be a real purple swan given your background beliefs, and yet it's very likely that all swans are white given what you believe about swans, then what you're observing must be very improbable — Pfhorrest
Which beliefs? I never believed that all my observations are accurate and unambiguous. What I believed prior to seeing the purple swan was that some observations turn out to be true and others don't. — Isaac
P(A|B) is not the same as P(A and B). — Isaac
So you were not surprised by the apparently purple swan, and it was consistent with your prior beliefs? Then you have no contradictory observations to falsify anything. You just saw something consistent with your expectations. — Pfhorrest
I never said it was. I say that the probabilistic equivalent of a conditional statement is a conditional probability: the probabilistic equivalent of "B if A" is "P(B|A)". (I did misleadingly say that "P(B|A)" was equivalent to "P(B if A)", but that was for a natural-language reading of "B if A", and that equivalency is only problematic when "B if A" is taken as a strict material implication). — Pfhorrest
This still accords with Bayesian reasoning, because you could reason along the same lines, but probabilistically instead of in those absolute statements. If the thing you're observing is very likely to be a real purple swan given your background beliefs, and yet it's very likely that all swans are white given what you believe about swans, then what you're observing must be very improbable. — Pfhorrest
Neither confirmationists, nor fideists, nor nihilists, nor any of your stated targets believe they can predict the future with 100% percent accuracy. So none of them are disproven by your statement that observing something surprising contradicts a belief (an expectation) that we wouldn't. — Isaac
You're saying that the probability of A and B ("then what you're observing must be very improbable") is P(A and B) — Isaac
But it's also possible that different processes for coming up with beliefs will be more or less productive in coming up with beliefs that are unlikely to be falsified. Believing that patterns you've observed are likely to continue (i.e. induction) could very well be one of those safer methods (and I'm intuitively inclined to say it probably is, but I don't have any arguments to that effect). — Pfhorrest
I’m saying that if you see something and think “whoa a black swan, I didn’t think those were possible...” and then either “I guess they are possible after all” or “it must be fake somehow”, you’ve revised the beliefs you initially had. — Pfhorrest
So, here's a great example: you cite just two possibilities; the impossibility that the laws of nature could have suddenly changed and things might just morph at random from white to black to purple or whatever is implicit in the way you arrive at what you consider possible. This is entirely on account of inductive expectation; it's not logically prescribed that the laws of nature cannot change. — Janus
More generally though, on this topic of the laws of nature not changing: that is not something we believe because of induction, but something we must believe to do induction. If we don’t assume that that’s the case, then there is no reason to expect patterns to continue as we have seen them do thus far. — Pfhorrest
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