If you want some philosophical foundation, I suppose the first step is to decide whether probability is in the mind, or in the territory.
The MWI/Tegmark approaches are trying to find probability in the territory; to define it as a frequency among some possible worlds.
The opposite approach is to define probabilities as a tool to deal with uncertainty. You can have uncertainty regardless of the underlying structure of the universe. (You could even have uncertainty about the underlying structure of the universe.) If thinking creatures can evolve in Conway’s deterministic Game of Life, they too could be uncertain about some stuff, and could invent probability to describe their uncertainty.
Huh, I thought that many people supported both a Tegmark IV multiverse as well as a Bayesian interpretation of probability theory, yet you list them as opposite approaches?
I suppose my current philosophy is that the Tegmark IV multiverse does exist, and probability refers to the credence I should lend to each possible world that I could be embedded in (this assumes that “I” am localized to only one possible world). This seems to incorporate both of the approaches that you listed as “opposite”.
To be precise, I think that MWI is probably true in our reality, but I think that probability is subjective and unrelated to whether MWI is true or false.
Like, if the MWI is true, then for a hypothetical omniscient and perfectly calibrated being probabilities would be equal to frequencies of Everett branches. But if e.g. Copenhagen interpretation is true, then for the same being, probabilities would be equal to… uhm, probabilities in the collapse. And if we lived in the Conway’s Game of Life, then I guess the hypothetical omniscient being could predict everything with 100% certainty, so the concept of probability would not make sense for them, but it would still make sense for beings with imperfect knowledge.
In other words, probability is in the mind, but hypothetically speaking if your mind is god-like then your probability reflects something in the territory (because what else it could be?).
In other words, probability is in the mind, but hypothetically speaking if your mind is god-like then your probability reflects something in the territory (because what else it could be
Why not summarise that as “in the mind and in the territory”.
A better summary is “in the mind and maybe parts of the territory”. It definitely exists in the mind. We don’t know how to test when and whether it’s in the territory.
If you want some philosophical foundation, I suppose the first step is to decide whether probability is in the mind, or in the territory.
The MWI/Tegmark approaches are trying to find probability in the territory; to define it as a frequency among some possible worlds.
The opposite approach is to define probabilities as a tool to deal with uncertainty. You can have uncertainty regardless of the underlying structure of the universe. (You could even have uncertainty about the underlying structure of the universe.) If thinking creatures can evolve in Conway’s deterministic Game of Life, they too could be uncertain about some stuff, and could invent probability to describe their uncertainty.
“In the mind” and “in the territory” aren’t mutually exclusive , and words dont have to have a single meaning.
Huh, I thought that many people supported both a Tegmark IV multiverse as well as a Bayesian interpretation of probability theory, yet you list them as opposite approaches?
I suppose my current philosophy is that the Tegmark IV multiverse does exist, and probability refers to the credence I should lend to each possible world that I could be embedded in (this assumes that “I” am localized to only one possible world). This seems to incorporate both of the approaches that you listed as “opposite”.
To be precise, I think that MWI is probably true in our reality, but I think that probability is subjective and unrelated to whether MWI is true or false.
Like, if the MWI is true, then for a hypothetical omniscient and perfectly calibrated being probabilities would be equal to frequencies of Everett branches. But if e.g. Copenhagen interpretation is true, then for the same being, probabilities would be equal to… uhm, probabilities in the collapse. And if we lived in the Conway’s Game of Life, then I guess the hypothetical omniscient being could predict everything with 100% certainty, so the concept of probability would not make sense for them, but it would still make sense for beings with imperfect knowledge.
In other words, probability is in the mind, but hypothetically speaking if your mind is god-like then your probability reflects something in the territory (because what else it could be?).
I don’t think we have a substantial disagreement.
Why not summarise that as “in the mind and in the territory”.
A better summary is “in the mind and maybe parts of the territory”. It definitely exists in the mind. We don’t know how to test when and whether it’s in the territory.
In the mind that is trying to reflect the territory.