Memories are knowledge—they are knowledge about past perceptions. They have been lost—because they have been chemically deleted by the amnesia-inducing drug. If they had not been lost, Beauty’s probability estimates would be very different at each interview—so evidently the lost information was important in influencing Beauty’s probability estimates.
That should be all you need to know to establish that the deletion of Beauty’s memories changes her priors, and thereby alters her subjective probability estimates. Beauty awakens, not knowing if she has previously been interviewed—because of her memory loss. She knew whether she had previously been interviewed at the start of the experiment—she hadn’t. So: that illustrates which memories have been deleted, and why her uncertainty has increased.
Yes. The memories have been lost (and the knowledge that accompanies them). The knowledge of what day of the week it is has not been lost because she never had this… as I’ve said four times. I’m just going to keep referring you back to my previous comments because I’ve addressed all this already.
You seem to have got stuck on this “day of the week” business :-(
The point is that beauty has lost knowledge that she once had—and that is why her priors change. That that knowledge is “what day of the week it currently is” seems like a fine way of thinking about what information beauty loses to me. However, it clearly bugs you—so try thinking about the lost knowledge another way: beauty starts off knowing with a high degree of certainty whether or not she has previously been interviewed—but then she loses this information as the experiment progresses—and that is why her priors change.
This example, like the last one, is indexed to a specific time. You don’t lose knowledge about conditions at t1 just because it is now t2 and the conditions are different.
Beauty loses information about whether she has previously attended interviews because her memories of them are chemically deleted by an amnesia-inducing drug—not because it is later on.
“No knowledge has been lost”?!?
Memories are knowledge—they are knowledge about past perceptions. They have been lost—because they have been chemically deleted by the amnesia-inducing drug. If they had not been lost, Beauty’s probability estimates would be very different at each interview—so evidently the lost information was important in influencing Beauty’s probability estimates.
That should be all you need to know to establish that the deletion of Beauty’s memories changes her priors, and thereby alters her subjective probability estimates. Beauty awakens, not knowing if she has previously been interviewed—because of her memory loss. She knew whether she had previously been interviewed at the start of the experiment—she hadn’t. So: that illustrates which memories have been deleted, and why her uncertainty has increased.
Yes. The memories have been lost (and the knowledge that accompanies them). The knowledge of what day of the week it is has not been lost because she never had this… as I’ve said four times. I’m just going to keep referring you back to my previous comments because I’ve addressed all this already.
You seem to have got stuck on this “day of the week” business :-(
The point is that beauty has lost knowledge that she once had—and that is why her priors change. That that knowledge is “what day of the week it currently is” seems like a fine way of thinking about what information beauty loses to me. However, it clearly bugs you—so try thinking about the lost knowledge another way: beauty starts off knowing with a high degree of certainty whether or not she has previously been interviewed—but then she loses this information as the experiment progresses—and that is why her priors change.
This example, like the last one, is indexed to a specific time. You don’t lose knowledge about conditions at t1 just because it is now t2 and the conditions are different.
Beauty loses information about whether she has previously attended interviews because her memories of them are chemically deleted by an amnesia-inducing drug—not because it is later on.