A set of beliefs is not like a bag of sand, individual beliefs unconnected with each other, about individual things. They are connected to each other by logical reasoning, like a lump of sandstone. Not all beliefs need to have a direct connection with experience, but as long as pulling on the belief pulls, perhaps indirectly, on anticipated experience, the belief is meaningful.
When a pebble of beliefs is completely disconnected from experience, or when the connection is so loose that it can be pulled around arbitrarily without feeling the tug of experience, then we can pronounce it meaningless. The pebble may make an attractive paperweight, with an intricate structure made of elements that also occur in meaningful beliefs, but that’s all it can be. Music of the mind, conveying a subjective impression of deep meaning, without having any.
For the hypothetical photon disappearing in the far-far-away, no observation can be made on that photon, but we have other observations leading to beliefs about photons in general, according to which they cannot decay. That makes it meaningful to say that the far away photon acts in the same way. If we discovered processes of photon decay, it would still be meaningful, but then we would believe it could be false.
Interesting idea. But how did you know how to phrase your original beliefs about photons? You could just have easily decided to describe photons as “photons obey Maxwell’s equations up to an event horizon and case to exist outside of it”. You could then add other beliefs like “nothing exists outside of the event horizon” which are incompatible with the photon continuing to exist.
In other words, your beliefs cannot afford to be independent of one another, but you could build two different belief systems, one in which the photon continues to exist and one in which it does not, that make identical predictions about experiences. Is it meaningful to ask which of these belief systems is true?
But how did you know how to phrase your original beliefs about photons? You could just have easily decided to describe photons as “photons obey Maxwell’s equations up to an event horizon and case to exist outside of it”.
Systems of belief are more like a lump of sandstone than a pile of sand, but they are also more like a lump of sandstone, a rather friable lump, than a lump of marble. They are not indissoluble structures that can be made in arbitrary shapes, the whole edifice supported by an attachment at one point to experience.
Experience never brought hypotheses such as you suggest to physicists’ attention. The edifice as built has no need of it, and it cannot be bolted on: it will just fall off again.
But these hypotheses have just be brought to our attention—just now. In fact the claim that these hypotheses produce indistinguishable physics might even be useful. If I want to simulate my experiences, I can save on computational power by knowing that I no longer have to keep track of things that have gone behind an event horizon. The real question is why the standard set of beliefs should be more true or meaningful than this new one. A simple appeal to what physicists have so far conjectured is not in general sufficient.
Which meaningful beliefs to consider seriously is an issue separate from the original koan, which asks which possible beliefs are meaningful. I think we are all agreeing that a belief about the remote photon’s extinction or not is a meaningful one.
I don’t see how you can claim that the belief that the photon continues to exist is a meaningful belief without also allowing the belief that the photon does not continue to exist to be a meaningful belief. Unless you do something along the lines of taking Kolmogorov complexity into account, these beliefs seem to be completely analogous to each other. Perhaps to phrase things more neutrally, we should be asking if the question “does the photon continue to exist?” is meaningful. On the one hand, you might want to say “no” because the outcome of the question is epiphenomenal. On the other hand, you would like this question to be meaningful since it may have behavioral implications.
I don’t see how you can claim that the belief that the photon continues to exist is a meaningful belief without also allowing the belief that the photon does not continue to exist to be a meaningful belief.
They’re both meaningful. There are reasons to reject one of them as false, but that’s a separate issue.
OK. I think that I had been misreading some of your previous posts. Allow me the rephrase my objection.
Suppose that our beliefs about photons were rewritten as “photons not beyond an event horizon obey Maxwell’s Equations”. Making this change to my belief structure now leaves beliefs about whether or not photons still exist beyond an event horizon unconnected from my experiences. Does the meaningfulness of this belief depend on how I phrase my other beliefs?
Also if one can equally easily produce belief systems which predict the same sets of experiences but disagree on whether or not the photon exists beyond the event horizon, how does this belief differ from the belief that Carol is a post-utopian?
In other words, your beliefs cannot afford to be independent of one another, but you could build two different belief systems, one in which the photon continues to exist and one in which it does not, that make identical predictions about experiences. Is it meaningful to ask which of these belief systems is true?
Dunno about “meaningful”, but the model with lower Kolmogorov complexity will give you more bang for the buck.
Your view reminds me of Quine’s “web of belief” view as expressed in “Two Dogmas of Empiricism” section 6:
The totality of our so-called knowledge or beliefs, from the most casual matters of geography and history to the profoundest laws of atomic physics or even of pure mathematics and logic, is a man-made fabric which impinges on experience only along the edges. Or, to change the figure, total science is like a field of force whose boundary conditions are experience. A conflict with experience at the periphery occasions readjustments in the interior of the field. Truth values have to be redistributed over some of our statements. Reevaluation of some statements entails reevaluation of others, because of their logical interconnections—the logical laws being in turn simply certain further statements of the system, certain further elements of the field.
Quine doesn’t use Bayesian epistemology, unfortunately because I think it would have helped him clarify and refine his view.
One way to try to flesh this intuition out is to say that some beliefs are meaningful by virtue of being subject to revision by experience (i.e. they directly pay rent), while others are meaningful by virtue of being epistemically entangled with beliefs that pay rent (in the sense of not being independent beliefs in the probabilistic sense). But that seems to fail because any belief connected to a belief that directly pays rent must itself be subject to revision by experience, at least to some extent, since if A is entangled with B, an observation which revises P(A) typically revises P(B), however slightly.
A set of beliefs is not like a bag of sand, individual beliefs unconnected with each other, about individual things. They are connected to each other by logical reasoning, like a lump of sandstone. Not all beliefs need to have a direct connection with experience, but as long as pulling on the belief pulls, perhaps indirectly, on anticipated experience, the belief is meaningful.
When a pebble of beliefs is completely disconnected from experience, or when the connection is so loose that it can be pulled around arbitrarily without feeling the tug of experience, then we can pronounce it meaningless. The pebble may make an attractive paperweight, with an intricate structure made of elements that also occur in meaningful beliefs, but that’s all it can be. Music of the mind, conveying a subjective impression of deep meaning, without having any.
For the hypothetical photon disappearing in the far-far-away, no observation can be made on that photon, but we have other observations leading to beliefs about photons in general, according to which they cannot decay. That makes it meaningful to say that the far away photon acts in the same way. If we discovered processes of photon decay, it would still be meaningful, but then we would believe it could be false.
Interesting idea. But how did you know how to phrase your original beliefs about photons? You could just have easily decided to describe photons as “photons obey Maxwell’s equations up to an event horizon and case to exist outside of it”. You could then add other beliefs like “nothing exists outside of the event horizon” which are incompatible with the photon continuing to exist.
In other words, your beliefs cannot afford to be independent of one another, but you could build two different belief systems, one in which the photon continues to exist and one in which it does not, that make identical predictions about experiences. Is it meaningful to ask which of these belief systems is true?
Systems of belief are more like a lump of sandstone than a pile of sand, but they are also more like a lump of sandstone, a rather friable lump, than a lump of marble. They are not indissoluble structures that can be made in arbitrary shapes, the whole edifice supported by an attachment at one point to experience.
Experience never brought hypotheses such as you suggest to physicists’ attention. The edifice as built has no need of it, and it cannot be bolted on: it will just fall off again.
But these hypotheses have just be brought to our attention—just now. In fact the claim that these hypotheses produce indistinguishable physics might even be useful. If I want to simulate my experiences, I can save on computational power by knowing that I no longer have to keep track of things that have gone behind an event horizon. The real question is why the standard set of beliefs should be more true or meaningful than this new one. A simple appeal to what physicists have so far conjectured is not in general sufficient.
Which meaningful beliefs to consider seriously is an issue separate from the original koan, which asks which possible beliefs are meaningful. I think we are all agreeing that a belief about the remote photon’s extinction or not is a meaningful one.
I don’t see how you can claim that the belief that the photon continues to exist is a meaningful belief without also allowing the belief that the photon does not continue to exist to be a meaningful belief. Unless you do something along the lines of taking Kolmogorov complexity into account, these beliefs seem to be completely analogous to each other. Perhaps to phrase things more neutrally, we should be asking if the question “does the photon continue to exist?” is meaningful. On the one hand, you might want to say “no” because the outcome of the question is epiphenomenal. On the other hand, you would like this question to be meaningful since it may have behavioral implications.
They’re both meaningful. There are reasons to reject one of them as false, but that’s a separate issue.
OK. I think that I had been misreading some of your previous posts. Allow me the rephrase my objection.
Suppose that our beliefs about photons were rewritten as “photons not beyond an event horizon obey Maxwell’s Equations”. Making this change to my belief structure now leaves beliefs about whether or not photons still exist beyond an event horizon unconnected from my experiences. Does the meaningfulness of this belief depend on how I phrase my other beliefs?
Also if one can equally easily produce belief systems which predict the same sets of experiences but disagree on whether or not the photon exists beyond the event horizon, how does this belief differ from the belief that Carol is a post-utopian?
Dunno about “meaningful”, but the model with lower Kolmogorov complexity will give you more bang for the buck.
Your view reminds me of Quine’s “web of belief” view as expressed in “Two Dogmas of Empiricism” section 6:
Quine doesn’t use Bayesian epistemology, unfortunately because I think it would have helped him clarify and refine his view.
One way to try to flesh this intuition out is to say that some beliefs are meaningful by virtue of being subject to revision by experience (i.e. they directly pay rent), while others are meaningful by virtue of being epistemically entangled with beliefs that pay rent (in the sense of not being independent beliefs in the probabilistic sense). But that seems to fail because any belief connected to a belief that directly pays rent must itself be subject to revision by experience, at least to some extent, since if A is entangled with B, an observation which revises P(A) typically revises P(B), however slightly.