Comments

  • Has Wittgenstein changed your life?
    Not only by science. "It is raining" is an empirical proposition that is verified by looking outside your window.Agustino

    A life changing revelation indeed!
  • Has Wittgenstein changed your life?
    Every objective statement is a proposition verified by science.Question

    Including scientific theories?
  • Existence
    And if you adhere to the Goat Theory of the Universe, you can say it exists, if it is a goat.Banno

    But only if it's a holographic goat!
  • Existence
    Holographic patterns. As if this forum were for failed physicists.Banno

    Exactly, it's for failed philosophers!
  • Existence
    The wave is the pattern.Rich

    How can a wave BE a holographic pattern?
  • Existence
    Everything would be holographic.Rich

    How can a wave have a holographic pattern inside it?
  • Existence
    I'm also reading a book which says that causes do not exist! Patterns exist. If causes do not exist, then to exist is not to be causally relevant. If we accept patterns exist instead of causes, would it make sense to say that to exist is to be part of a pattern?mew

    Is that David Hume's "An Enquiry Concerning Human Understanding" (1739)?
  • Existence
    A holographic pattern within universal waves would be the defining aspect of existence, but one must first embrace the holographic model of the universe and memory.Rich

    I see, a pattern within universal waves that happens to be holographic defines existence.

    Where does one encounter these waves, and how does one tell that a pattern within them is holographic?
  • Existence
    If there is some memory of it, it exists. If you are an adherent of the holographic model of the universe, you can say that it exists, if there is a holographic pattern of it.Rich

    What do holograms have to do with whether something exists or not?
  • The Raven Paradox
    You said:

    K is compatible with any evidence. p(E|K) is still 1, and (KE) and (K) have the same truth value. I certainly seems weaker, but I can see no reason that K does not logically imply E, just as it implies not(E).

    You might regard this as a more formal statement:

    K => E iff p(E|KB) = 1 for every B

    My original concerns stand. K is a hypothesis which is supposedly compatible with "any evidence," which is completely at odds with its being falsifiable (indeed, this seems to smuggle your conclusion into the proof itself, thereby begging the question).
    Arkady

    Well, you were asking about p(HE|B), which, as I said, I had already covered.

    The observation of a green apple, or a black raven - the corroborating evidence - is logically implied by H, and by K.

    The "more formal statement" above is actually a definition of logical implication.

    If you don't like the "not all ravens are black" fro some reason, then change it. There are several others you could chose, "all ravens are black except the white ones", "all ravens are black or white".
  • The Raven Paradox
    A hypothesis can be confirmed by evidence but still turn out to be false. "Confirmation" is not equivalent to "verification." The observation of a single non-white raven falsifies the hypothesis that all ravens are black.Arkady

    So, what happens to the millions of "confirmations"?

    And, why am I still seeing them? I can literally look at green apples whenever I want.
  • A Simple Argument against Dualism
    In this sense QM is a kind of 'card' that sophisticated parlor gamers overrule, perhaps justifiably, with a disdain 'card.'csalisbury

    The irony being that, according to quantum mechanics, quantum coherence cannot have any bearing on the operation of the human mind.
  • A Simple Argument against Dualism
    But then (drawing obviously from an emergentist vein) How do hurricanes and representative democracies interact? Stock markets and Film Festival circuits?

    These questions all seem to involve form as much - if not more - than the material. And it's not like the mind is formless. But it still seems another step to then say the mind isn't supervenient on matter, the same matter that anything else, that exists, supervenes on. But maybe that's just because it would make the mind seem too free of limitation, formless.
    csalisbury

    Isn't dualism simply the assertion that, despite all the things we know that supervene on matter, including film festivals, there is one thing, namely the human mind, that cannot supervene on the physical?

    Considering that Life itself is known to supervene on the physical, it seems a bit outrageous to claim that the "mind" of a particular species cannot.
  • The Raven Paradox
    Just curious. What happens to the millions of "confirmations" that "all ravens are black", by observing not only black ravens but literally every non-black non-raven thing you have ever seen, when you encounter these?

    white-raven5.jpg
  • The Raven Paradox
    But, that's part of the paradox. Green apples are not unrelated to the universal statement "all ravens are black." It confirms the (logically equivalent) contrapositive, i.e. that all non-black things are non-ravens.Arkady

    Green apples also "confirm" the universal statement "all ravens are white".

    Now that I think of it, I may have found another problem: you claim that H entails E, and so that p(he|b) = p(h|b). But, I'm not sure that this follows. Even if H entails E, unless they are necessary truths, the probability of their conjunction must be equal to or less than either of the conjuncts. P(H|E) or P(E|H) are not equal to P(H&E), even when H entails E (that is, P(E|H) = 1).Arkady

    I covered that earlier.

    Right...hence the paradox! It's counterintuitive (to put it mildly) that the observation of green apples confirms the hypothesis that all ravens are black.Arkady

    It's not counterintuitive it is just wrong. If green apples "confirm" "black ravens", they also confirm "white ravens".

    Let us not forget that the universal statement "all ravens are black" is in fact false!
  • The Raven Paradox
    So, you are in essence saying that the same evidence would confirm "all ravens are black" as would confirm "not all ravens are black") (i.e. H and K, respectively, which constitute the hypothesis and its negation). I don't see how that could possibly be the case.Arkady

    We have a situation where the observation of a green apple purportedly supports an enormous number of unrelated universal statements, including the statement "all ravens are black". The solution to this problem is to recognise that there is no such thing as epistemologically valuable corroborating evidence. It simply cannot exist.

    The corroborating evidence E points everywhere and thus nowhere. For some psychological reason we see this in the case of green apples, but not in black ravens.
  • The Raven Paradox
    I have some questions about this. I don't see how H (hypothesis) logically implies E (evidence).Arkady

    Well spotted!

    A couple of things:

    The truth value of H and HE are the same, because H logically implies E

    p(HE) = p(H)*p(E|H)

    The probability of E given that H is in fact true is 1, because H logically implies E.

    So by Bayes theorem

    p(HE|B) = p(B|HE)P(HE)/P(B)

    = p(B|H)p(H)/p(B) = p(H|B)

    Also, in order for the posterior probabilities not to matter here (because E cancels out), H and K must somehow imply the same "E". But, how can a hypothesis and its negation imply the same observational consequences?Arkady

    Even better!

    K is compatible with any evidence. p(E|K) is still 1, and (KE) and (K) have the same truth value. I certainly seems weaker, but I can see no reason that K does not logically imply E, just as it implies not(E).

    You might regard this as a more formal statement:

    K => E iff p(E|KB) = 1 for every B

    Also, the construction P(H&E|B) to describe confirmation seems odd. Wouldn't P(H|E&B) be more appropriate?Arkady

    That's in all the equations!
  • The Raven Paradox
    No, but I can see why you misunderstood me. The universal proposition is "if something is not black then it is not a raven"; i.e., "all non-black things are non-ravens." The proposition that I find unobjectionable is "for any randomly selected non-black thing, the probability is 0.5 that it will not be a raven." This is not the same (universal) proposition; it is instead a particular proposition, "some non-black things are non-ravens," with the additional information that the proportion of non-black things that are non-ravens is 50%.aletheist

    And, strange as it may seem, such probabilistic statements, which make no prediction about what will happen, are normative.
  • The Raven Paradox
    No, but I can see why you misunderstood me. The universal proposition is "if something is not black then it is not a raven"; i.e., "all non-black things are non-ravens." The proposition that I find unobjectionable is "for any randomly selected non-black thing, the probability is 0.5 that it will not be a raven." This is not the same (universal) proposition; it is instead a particular proposition, "some non-black things are non-ravens," with the additional information that the proportion of non-black things that are non-ravens is 50%.aletheist

    Probability is a complete red herring until someone states the prior and tells us how to update it.

    Then they need to explain why we should set our credence to be equal to the probability. (hint look up the Principal Principle)

    Then someone needs to explain how we can test a probability statement, what deviations from the expectation value we are willing to accept, and why.

    Then someone might deign to explain why a "probable" theory is "probably true"

    Then this

    031.jpg
  • The Raven Paradox
    And the above interpretation is wrong. When I say that the probability that "if something is not black then it is not a raven" is true is 0.5 I mean that that for any randomly selected non-black thing, the probability is 0.5 that it will not be a raven.Michael

    How many non-black things do you need to select to show that your assertion that the probability of selecting a non-raven is 0.5?
  • The Raven Paradox
    I don't think so, Tom. I'll let you quote one that rules that not to be a universal. I'll even modify it a bit for you: All unenlightened's pockets everywhere in the universe are empty.unenlightened

    Since you won't consult an elementary text, let me help you:

    A universal statement is one in which no individual names occur.

    Got it?
  • The Raven Paradox
    The difference is that you actually observed all of your pockets. The OP is claiming that a single observation provides evidential support for a universal proposition. Tom's proof shows that this is not the case - but it no longer applies once you have observed all members of the class, at which point you know whether the universal proposition is true (p=1) or false (p=0).aletheist

    In the proof I gave, observation of your own pockets would constitute background knowledge. The hypothesis would be the universal statement "all pockets are empty". I guess you could then set about gathering evidence.
  • The Raven Paradox


    Sure, all ravens in Vienna in 1938 were also black. Perhaps you should consult an elementary text on universal statements?
  • The Raven Paradox
    Why do you keep addressing this to me? My statement that you quoted has absolutely nothing to do with universal propositions. Observation of a green apple merely proves that the particular proposition, "some non-black things are non-ravens," is true (p=1).aletheist

    My apologies!

    Anyway, the paradox is solved.
  • The Raven Paradox
    I said that the observation of a green apple only supports - in fact, proves - the particular proposition that some non-black things are non-ravens.aletheist

    I have just proved that observational support for for a universal statement is impossible. If you think such support exists, and in particular that the observation of green apples provide support for any such statement, you have just been proved wrong.

    And the paradox is solved of course.
  • The Raven Paradox
    Notice that the observation of a green apple can have no effect whatsoever on any of these probabilities. It only tells us that the probability that non-black non-ravens exist is 1; i.e., some non-black things are non-ravens.aletheist

    I beg to differ! If there is such a thing as probabilistic support for a universal statement, then green apples do indeed support "all ravens are black". I have given the solution to this paradox earlier in the thread, so now let me prove it:

    A well known result from probability calculus is:

    p(he|b) = p(h|eb)p(eb)

    Let h = "all ravens are black" i.e. the hypothesis
    Let b = background knowledge e.g. all the ravens previously encountered
    Let e = new evidence - the sighting of another raven

    h logically implies e, so "h and e" is equivalent to h, so

    p(h|b) = p(h|eb)p(eb)

    Thus

    p(h|eb)=p(h|b)/p(eb)

    Do this again with an alternative hypothesis:

    k = "NOT all ravens are black"

    And divide one expression by the other, you get:

    p(h|eb)/p(k|eb) = p(h|b)/p(k|b)

    Now notice that no matter how h and k generalize under new evidence e, the evidence is incapable of affecting the ratio of their probabilities! What you are left with is the ratio of the prior probabilities, which you can have done nothing except arbitrarily set.

    Thus there is no such thing as probabilistic support for a universal statement!
  • The Raven Paradox
    It doesn't matter how weak the evidence is. The paradox is that there's evidence at all.Michael

    And the paradox is resolved by recognising, with Hume, that there is no such thing as evidence for a universal proposition. The "paradox" reveals the absurdity of claiming empirical support exists.

    The mild irony is however, that we know the statement that "all ravens are black" is in fact false, and no number of green apples is going to change that.
  • The Raven Paradox
    1. The proposition that if something is a raven then it is black is logically equivalent to the proposition that if something is not black then it is not a raven.

    2. The existence of green apples is evidence (even if weak) that the proposition that if something is not black then it is not a raven is true.
    Michael

    2. Is false. There is no such thing as evidence for a universal statement. What's more, you can't apply probabilities to universal statements.

    In the case where the universal statement is an hypothesis - i..e a tentative explanation for some aspect of reality, you can't use probabilities either. The negation of an explanation is not an explanation, so the two are in different classes of objects. In such circumstances attributing (p) to an explanation and (1-p) to its negation is meaningless.
  • The Raven Paradox
    The vast majority of people have a relevance requirement for evidence. The purported evidence needs to have something to do with what it's evidence for.Terrapin Station

    Newton's law of gravitation accumulated a vast amount of evidence in support over many years. Applying the purported probability calculus to it, it must have achieved the status of a highly probable theory by 1915.

    Then what happened? Is it still a highly probable?
  • The Raven Paradox
    As the maths shows, each successful observation increases the probability of the assertion being true, and as such counts as evidence (even if weak evidence).Michael

    What probability would you ascribe to Newton's theory of gravitation in 1915?
  • A Simple Argument against Dualism
    I know they would deny (4). Propositions (1)-(3) were supposed to encompass what substance dualists do believe.Arkady

    Not sure substance dualists believe that though, if there are any that is.
  • A Simple Argument against Dualism
    And my question could be applied to any metaphysical thesis (or even any philosophical thesis whatsoever, I suppose). If a thesis has a central, potentially fatal problem, which hundreds of years of theorizing have failed to resolve, does that lead to a justifiably diminished confidence that said thesis is correct (or whatever passes for "correct" with regard to philosophical theses)?Arkady

    I think it is wrong to characterise Dualism as a metaphysics which has made zero progress. Did we not think once that life and non-live were different substances, body and soul, heaven and earth, etc. It seems a great deal of progress has been made.

    Dualism's persistence may be due to the fact that it is a generic method of retreat from problems. What is to stop you claiming anything is due to some substance that interacts with physical reality by mysterious means? And, you can always move the goalposts.
  • A Simple Argument against Dualism
    Speaking as a physics layman, my understanding is that theorists have been struggling to reconcile QM and relativity, as the theories work well in their own domains, but break down into nonsense when one attempts to integrate the theories (something about crazy infinities popping up all over the place, I think). Given this failure of reconciliation, would it not follow that at least one of theories (QM or relativity) are false?Arkady

    At least one has to be false, presumably both are. But, we have scores of predictions from the theories, all of which are true. E.g. All the fundamental particles and their interactions, entanglement, teleportation, no-cloning, decoherence, big-bang, black-holes, cosmic microwave background, gravitational waves, ... None of these unexpected features of reality are going to go away.

    As for the theories breaking down into nonsense, well they don't. They don't to the extent that there are experiments (BICEP2) looking into pre-big-bang signals in the CMB.

    So, the extent to which either theory is false is the extent to which either is an extremely good approximation to a deeper theory. Despite LHC and many other efforts, no observation that renders either theory problematic has been made.

    Of these three propositions (3) would seem to be on the most secure footing, and is therefore the least likely to be false.Arkady

    Leibniz thought it was false. Does that make it any less likely?
  • A Simple Argument against Dualism
    The problem is that there's no non-physical account of how anything is supposed to work.Terrapin Station

    Quite, but perhaps it might be more accurate to say that there are no good non-physical accounts. By "good" I mean an account that is difficult to modify and still account for the explicanda.

    e.g. The mind interacts with physical reality via pre-established harmony, or angels, of rays that only conscious brains can detect, etc.

    The hard problem is precisely hard because of the rigorous demands physicalism imposes on its explanations.

    Dualists seem happy to state at a word re-definition and think they have achieved something.
  • The Raven Paradox
    Evidence?

  • A Simple Argument against Dualism
    Yes. But the "computer playing chess" is our abstraction of the mechanical events occurring inside the computer.Michael

    If a computer is controlling a power station or a refinery, is that "controlling a power station" our abstraction or is it really controlling a power station?
  • A Simple Argument against Dualism
    The "chess program" is our abstraction of the mechanical events occurring inside the computer.Michael

    Is the computer playing chess or not? If so, how?
  • A Simple Argument against Dualism
    Consider: the question of how something material and something non-material can possibly interact seems to presuppose that it is clear how two material things interact. But why can we not equally ask, how is it that two separate things in space, apart from one another, come into interaction?The Great Whatever

    The interaction is by what we call forces. Three of them are by particle exchange, two of which only operate on the sub-atomic scale. The fourth interaction is arguably not a force, but an effect of space-time geometry.

    If you say, because we define causality that way, then this is not good enough, for then we can just defined causality so as to include interaction between the mental and physical, seeing as we seem to have so many obvious instances of it, and you beg the question.The Great Whatever

    Physics does not define causality. Our fundamental laws are time-symmetric, so they can't include any conception like causality.

    Once you define causality to include the interaction between the mental and physical, then what are you going to do apart from stare at a definition?
  • A Simple Argument against Dualism
    The assumption is that causes and effects occur in space and time. Descartes defines minds as not being located in space and time. According to Descartes' definition of mind, minds can't be causes or effects. Interactions imply causation. So, Descartes' definition is wrong. In order to explain mind-body interaction, minds must be located in space and time. If minds are located in space and time, then Descartes' definition of mind is false, and dualism is false, too.quine

    I don't think you need to make any assumptions, or appeal to cause and effect. According to our knowledge there are only 4 forces that describe all interactions. If there were a 5th force, then this would necessarily be in physical reality, so Dualists would then require a 6th etc.

    However, when a computer is playing you at chess (or Go or poker) where exactly is the chess program? The program being of course an abstract algorithm to achieve an abstract outcome based on an abstract set of rules.
  • A Simple Argument against Dualism
    There is no 'interaction problem.' As Hume noted, even the problem of motion of bodies in different points of space is rationally inexplicable. There is a 'motion problem' just as much as there is an 'interaction problem.'The Great Whatever

    You don't happen to have a reference for that do you?

    Anyway, it's perhaps a little too much to expect anyone from the 1700s to anticipate modern science.