> On 6 Sep 2020, at 20:40, John Clark <johnkcl...@gmail.com> wrote: > > On Sun, Sep 6, 2020 at 9:34 AM Bruno Marchal <marc...@ulb.ac.be > <mailto:marc...@ulb.ac.be>> wrote: > > >> I don't know what the hell to make of a "objective probability of a > >> possible subjectivity”. > > > I give you an example. A person is multiplied by 100 and put in 100 > > different, but identical from inside rooms. Just the number of the room > > differs, like in some hostel. You seem to agree that, as long as they stay > > in the room, there is only one person. But the copies are asked to open the > > room, and the person was asked, before the experience what is the > > probability that when going out of the room, its number is prime. > > In that thought experiment there is no objective probability because John > Clark is always in a prime numbered room or John Clark is not. So there is > only subjective probability. There is a 100% chance John Clark will walk out, > look at the number on the door and see a prime number, and a 100% chance he > will not see a prime number.
You make the same error than Bruce (curiously enough). Because all the alternative are realised, you take as 1 the probability that you feel them. But if we do the experience, those who see that the number is prime, or that it is not prime, can understand that the prediction asked, (which is a prediction on possible subjective experiences, and not on body localisation) cannot be 100% for prime. Indeed the John Clark of room 1, 4, 6, 8, 9, … admits that their prediction (on their subjective experiences) are wrong, and that is what makes those probabilities on subjective experiences objective. That are personally refutable, and unless you negate the conscious experience, they make sense. > And the question "What is the probability I will see a prime number?" has no > answer because in this hypothetical the personal pronoun "I" is ambiguous. It is not ambiguous, or it is ambiguous in Everett too. The point is that it is the same “ambiguity”, i.e. indeterminacy of personal outcomes. > > However if you were to ask one of the individual John Clarks in one of those > rooms AFTER the duplication "What is the probability you will see a prime > number on the door when you walk out?" then that would be a legitimate > unambiguous question, and the answer would be 25% because there are 25 prime > numbers less than 100. In this case, there were no explicit duplication, as in the start they are all identical brain in the rooms, and you have agree that there is only one, non ambiguous person/consciousness. Let me ask you this: do you agree that if I can predict with certainty that I will be indeterminate about what I will see after opening the door of the reconstitution box, then, I am unambiguously already indeterminate on that outcome? If yes, you can no mire say that there is a unique person, when two brains run identically. If not, you get the point. > But that probability would just be a subjective probability because he is > either in a prime numbered room or he is not, So that probability figure must > just be a measure of that John Clark's ignorance. Which is the same as the one before the multiplication, as we have accepted that all copies are continuation of the candidate (we use the non transitive notion of personal identity on which we have always agreed on). In your sense of “subjective probability” here, Mechanism makes all probability subjective, even the frequentist notion, despite it is also an observable (after Graham-Hartle-Omnes-Griffith type of treatment). I have no problem with that. By objective, we can mean here 3p, or 1p-plural. That does not change the probability calculus. Bruno > > John K Clark > > -- > You received this message because you are subscribed to the Google Groups > "Everything List" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to everything-list+unsubscr...@googlegroups.com > <mailto:everything-list+unsubscr...@googlegroups.com>. > To view this discussion on the web visit > https://groups.google.com/d/msgid/everything-list/CAJPayv374jtaN-qwF4t6sw1PcN-1DtZpVRK%3DGNP%2BeCLSF-iknw%40mail.gmail.com > > <https://groups.google.com/d/msgid/everything-list/CAJPayv374jtaN-qwF4t6sw1PcN-1DtZpVRK%3DGNP%2BeCLSF-iknw%40mail.gmail.com?utm_medium=email&utm_source=footer>. -- You received this message because you are subscribed to the Google Groups "Everything List" group. To unsubscribe from this group and stop receiving emails from it, send an email to everything-list+unsubscr...@googlegroups.com. To view this discussion on the web visit https://groups.google.com/d/msgid/everything-list/F3027A3E-D46A-4702-9B4C-644EBA795FD7%40ulb.ac.be.
