There is no restriction on which view to take. You can choose to reason from your natural first-person perspective. You can reason from other people’s (or other thing’s) perspective. We can even imagine a perspective such as a god’s eye view and reason from there. What PBA argues is that once you choose a perspective/view, stick with it for the entire analysis. It’s like an axiomatic system. We can’t derive triangles’ internal angle sum as 180 from Euclidian geometry then use it in Ecliptic geometry.
Self-locating probabilities are invalid because they need both the first-person view AND the god’s eye view to formulate.
The answer is simple yet unsatisfying. In those situations, assuming the objective is simple self-interest, there is no rational choice to be made.
If we assume the objective is the combined interest of a proposed reference class, and we further assume every single agent in the reference class follows the same decision theory, then there would be a rational choice. However, that does not correspond to the self-locating probability. It corresponds to a probability that can be consistently formulated from the god’s eye view. E.g. the probability that a randomly chosen observer is simulated rather than the probability that “I” am simulated. Those two are distinctly different unless we mix the perspectives and accept some kind of anthropic assumption such as SSA or SIA.
the probability that a randomly chosen observer is simulated rather than the probability that “I” am simulated.
But if randomly chosen observer is simulated, and I am randomly chosen observer, I should be simulated?
Another way to reason here—in a situation where we can’t make a rational choice – is “meta-doomsday argument” which I discussed before: I assume that both alternatives have equal probabilities, based on logical uncertainty about self-location believes. E.g. it gives 5⁄12 for Sleeping Beauty.
There is no randomness in metaphysical sense: everything possible exists.
However, there is relation inside an observer which looks like randomness: For any thought “this is a dog” there a billion possible different observations of different dogs. In some sense it looks like that there are billion observers of the reference class dog-seers. This relation between macro interpretations and its micro variants, is similar to entropy and it is numerical and could be regarded as probabilities for practical purposes.
There are several not mutually exclusive and plausible theories which implies existence of everything.
If universe for whatever reason is infinite, then everything possible exist. If MWI is true, everything possible exist. If Bolztmann brains are possible, again, all possible observers do exist. If Tegmarks mathematical universe is possible, again, all possible observers do exist.
Moreover, the fact that I exist at all implies very large number of attempts to create an observer, including something like 10^500 universes with different physical laws, which itself implied the existence of some unlimited source of attempts to create different things.
There are several not mutually exclusive and plausible theories which implies existence of everything.
They could all be wrong.
Moreover, the fact that I exist at all implies very large number of attempts to create an observer, including something like 10^500 universes with different physical laws, which itself implied the existence of some unlimited source of attempts to create different things
There is also a metaphysical argument, not depending on any empirical data, so it is less likely to be wrong. It may be more difficult to explain but I will try.
I call the argument “the unboundedness of nothingness”. It goes as following:
1. The world as we see it, appeared from nothing via some unknown process.
2. “Nothing” doesn’t have any properties by definition, so it doesn’t have a counter of worlds which appeared from it.
3. Thus if it create one world, it will produce infinitely many of them, because its ability to create worlds can’t be exhausted or stopped.
Or, in other words, if everything-that-exists has finite size and its growth is limited by some force, there is a contradiction as such force will not be a part of everything-that-exist. Thus such force doesn’t exist.
The world as we see it, appeared from nothing via some unknown process.
“Nothing” doesn’t have any properties by definition, so it doesn’t have a counter of worlds which appeared from it
Absolute metaphysical “nothing” also has no powers and no properties, so it had no power or property of universe creation. (Popular accounts of cosmology talk about universes appearing from nothing , but that is a loose usage of language).
Ok, I suggested you three independent lines of reasoning which implies that everything possible exists (physical theories, self-sampling logic similar to presumptuous philosopher and the idea that if Big Bang happened once it should also happen uncountably many times.)
Also, If only limited number of thing exist, there should be ontological force which prevent them popping from existence—and given that we exist we know that such popping is possible. The only thing which can limit the number of appearing is God. Bingo, we just got new proof of God’s existence!
But jokes asides, we obviously can’t prove factually existence of everything as it is unobservable, but we could use logical uncertainty to estimate probability of such claim. It is much more probable that everything possible exists, as there are three independent ways argue for it, and also if we assume the opposite, we have to invent some “limiting force” similar to God, which has low apriori probability.
Based on these my confidence in “everything possible exists” is 80-90 per cent.
Ok, I suggested you three independent lines of reasoning which implies that everything possible exists
You never compared or contrasted with any small/single universe theory.
but we could use logical uncertainty to estimate probability of such claim. It is much more probable that everything possible exists,
On the same theme, you can’t say how much probability mass multiversal theories have, without knowing how much single universal theories have.
Based on these my confidence in “everything possible exists” is 80-90 per cent
On the same theme, how can that be a meaningful number when you have never even thought about the rival theories?
Also, If only limited number of thing exist, there should be ontological force which prevent them popping from existence
Everything is based on assumptions. You are making an “anything will happen so long as it is not prevented” assumption. Many philosophers in the early modern period made an opposite assumption … that nothing can happen without Sufficient Reason.
Any reasoning is based on some assumptions and it is not a problem. We may list these assumptions and convert the into constrains of the model (with some probabilities).
Ok, lets try to prove the opposite thing.
Firstly, Kant in “Critiques of pure reason” explored these topics of the universe infinity in space in time and find that both propositions could be equally proved (finite and infinite), from which he concluded that the topics can’t be solved and is beyond human knowledge. However, Kant suggested on the margins one more proof of modal realism (I cite here by memory): “If a thing is possible in all aspects, there is no difference between it and real thing”.
The strongest argument against the existence of everything is non-randmoness of our experiences. If I am randomly selected from all possible minds, my observations should be very chaotic as most random minds are just random. There are several conter-arguments here: related either to chains of observer-moments converging to less random mind, or different measure of different minds, or that selection process of self-aware minds is a source of antirandomness, or that we in fact are random but can’t observe it, of that the internal structure of an observer is something like a convolutional neural net where randomness is concentrated to inputs and “order” to output. I will not elaborate these arguments here as it will be very long.
Another line of reasoning is connected with idea of actuality. In it, only me-now is real, and everything else is just possible. This line of reasoning is plausible, but it is even more weird than modal realism.
Then again, the idea of (Christian) God which creates only a few worlds. Improbable.
During last year EA forum, the following prove of the finitness of the universe was suggested:
“1) Finite means that available compute in the quantum theoretic sense in our future light cone is finite.
2) The Bekenstein bound says the information in a region is bounded proportional to area.
3) The universe’s expnasion is accelerating, so the there is a finite region of space that determines our future light cone.
4) Quantum mechanics is reversible, so the information of our future light cone is finite.
5) Only finite compute can be done given a finite information bound without cycling.”
But it is applicable only to our universe, but not to other universes.
The strongest argument against the existence of everything is non-randmoness of our experiences. If I am randomly selected from all possible minds, my observations should be very chaotic as most random minds are just random. There are several conter-arguments here: related either to chains of observer-moments converging to less random mind, or different measure of different minds, or that selection process of self-aware minds is a source of antirandomness, or that we in fact are random but can’t observe it, of that the internal structure of an observer is something like a convolutional neural net where randomness is concentrated to inputs and “order” to output. I will not elaborate these arguments here as it will be very long
There seems to be a common pattern where you start off with an assumption that mispredicts experience , and then make a further assumption to fix the situation. But that’s one step backwards, one step forwards. You end up with a more complex theory than one that takes one step forward, and just predicts experience.
I haven’t said much about the object level issue. Im inclined to agree with the OP that anthropic probability doesn’t work. I haven’t seen you argue against small/single worlds except to quote a probability!
Any reasoning is based on some assumptions and it is not a problem
All reasoning is based on assumptions and it’s a problem, because it makes it hard to converge on beliefs, or ever settle questions.
There’s a partial solution, in that not all assumptions are equal , and not all numbers of assumptions are equal.
That’s a fairly traditional version of Occams Razor based on minimising the number, and maximising the likelihood of assumptions.
Kant suggested on the margins one more proof of modal realism (I cite here by memory): “If a thing is possible in all aspects, there is no difference between it and real thing”.
All arguments depend on assumptions ,and yours is no exception.
For one thing , you are assuming fairly strong realism about time. That’s not a feature of all theories, or even all multiversal theories. Tegmarks mathematical multiverse struggles to explain time as a subjective phenomenon.
Actually, I didn’t assume realism about time, but the language we use works this way. Popping into existence may relate to Boltzmann brains which don’t have time.
Prima facie, Boltzman brain theories don’t predict experience. People sometimes try to fix that problem by making additional assumptions about consciousnes, leveraging the fact that no one knows how consciousness works.
It may seem very natural to say “I” am a randomly chosen observer (from some proposed reference class). But keep in mind that is an assumption. PBA suggests that assumption is wrong. And if we reason from one consistent perspective such kind of assumptions are unnecessary.
Ok, let’s look at a real world example: “drivers in next lane are going faster” suggested by Bostrom. It is true from observer’s point of view but not true from the God’s view.
“The drivers in the next lane are going faster” is true both from a driver’s first-person view and from a god’s eye view. However, none of those two are self-locating probabilities. This is explained by PBA’s position on self-locating probabilities, by the link mentioned above.
The lane assignment can be regarded as an experiment. The lane with more vehicles assigned to it moves slower. Here, from a god’s eye view, if a random car is selected then the probability of it from the slow lane is higher. From a driver’s first-person view, “I” and the other drivers are in symmetrical positions in this lane assigning experiment. So the probability of me being in the slow lane is higher. According to PBA, both probabilities are valid. However, they are not the same concept, though they have the same value. (This point have been illustrated by Question 1 and Question 2 in the link above)
However, neither of them are self-locating probabilities in the anthropic context. Some anthropic reasoning suggests there is an innate reference class for indexicals like “I”. E.g. SSA assumes “I” can be considered a randomly chosen human from all humans. This requires both the first-person to identify “I” and a god’s eye view to do the choosing. It does not depend on any experiment. Compare this with the driver’s first-person view above, the reference class is all drivers on the road. It is defined by the lane assigning experiment. It does not even matter if other drivers are humans or not. They could be all pigs and they would still be in symmetrical positions with me. The PBA argues the self-locating probabilities are invalid. (This point has been demonstrated by Question 3 in the link above.)
Since we are discussing Nick Bostrom’s position, he made the explicit statement in “The Mysteries of Self-Locating Belief and Anthropic Reasoning” that an experiment is unnecessary in defining the reference class. We can always treat “I” as the result of an imaginary sampling process. This is in direct conflict with my PBA. According to PBA, anthropics is not an observation selection effect, just recognizing the perspective of reasoning.
Lastly, you are clearly interested in this topic. I just find the questions you raised have already been covered by the argument presented on my website. I can only recommend you give it a read. Because this question and answer model of communication is disproportionally effort heavy on my part. Cheers.
There is no restriction on which view to take. You can choose to reason from your natural first-person perspective. You can reason from other people’s (or other thing’s) perspective. We can even imagine a perspective such as a god’s eye view and reason from there. What PBA argues is that once you choose a perspective/view, stick with it for the entire analysis. It’s like an axiomatic system. We can’t derive triangles’ internal angle sum as 180 from Euclidian geometry then use it in Ecliptic geometry.
Self-locating probabilities are invalid because they need both the first-person view AND the god’s eye view to formulate.
Your intuition seems reasonable, but what about situations where I have to make a choice based on self-location believes?
The answer is simple yet unsatisfying. In those situations, assuming the objective is simple self-interest, there is no rational choice to be made.
If we assume the objective is the combined interest of a proposed reference class, and we further assume every single agent in the reference class follows the same decision theory, then there would be a rational choice. However, that does not correspond to the self-locating probability. It corresponds to a probability that can be consistently formulated from the god’s eye view. E.g. the probability that a randomly chosen observer is simulated rather than the probability that “I” am simulated. Those two are distinctly different unless we mix the perspectives and accept some kind of anthropic assumption such as SSA or SIA.
But if randomly chosen observer is simulated, and I am randomly chosen observer, I should be simulated?
Another way to reason here—in a situation where we can’t make a rational choice – is “meta-doomsday argument” which I discussed before: I assume that both alternatives have equal probabilities, based on logical uncertainty about self-location believes. E.g. it gives 5⁄12 for Sleeping Beauty.
What does it mean metaphysically to be a randomly chosen observer? Who’s doing the choosing? Does it mean that all the other counterparts are zombies?
Practically, it means difference in the expected probabilities of future observations. What is your opinion on these questions?
You didn’t answer the question as stated.
If you don’t know what the ontology of random selection is, how can you predict experience from it?
My opinion is that there are well defined defined multiversal theories , and poorly defined ones.
Ok, updated my world model and now I think that:
There is no randomness in metaphysical sense: everything possible exists.
However, there is relation inside an observer which looks like randomness: For any thought “this is a dog” there a billion possible different observations of different dogs. In some sense it looks like that there are billion observers of the reference class dog-seers. This relation between macro interpretations and its micro variants, is similar to entropy and it is numerical and could be regarded as probabilities for practical purposes.
Do you have a reason for believing that?
There are several not mutually exclusive and plausible theories which implies existence of everything.
If universe for whatever reason is infinite, then everything possible exist. If MWI is true, everything possible exist. If Bolztmann brains are possible, again, all possible observers do exist. If Tegmarks mathematical universe is possible, again, all possible observers do exist.
Moreover, the fact that I exist at all implies very large number of attempts to create an observer, including something like 10^500 universes with different physical laws, which itself implied the existence of some unlimited source of attempts to create different things.
They could all be wrong.
Not without many other assumptions.
List item
There is also a metaphysical argument, not depending on any empirical data, so it is less likely to be wrong. It may be more difficult to explain but I will try.
I call the argument “the unboundedness of nothingness”. It goes as following:
1. The world as we see it, appeared from nothing via some unknown process.
2. “Nothing” doesn’t have any properties by definition, so it doesn’t have a counter of worlds which appeared from it.
3. Thus if it create one world, it will produce infinitely many of them, because its ability to create worlds can’t be exhausted or stopped.
Or, in other words, if everything-that-exists has finite size and its growth is limited by some force, there is a contradiction as such force will not be a part of everything-that-exist. Thus such force doesn’t exist.
Absolute metaphysical “nothing” also has no powers and no properties, so it had no power or property of universe creation. (Popular accounts of cosmology talk about universes appearing from nothing , but that is a loose usage of language).
Ok, I suggested you three independent lines of reasoning which implies that everything possible exists (physical theories, self-sampling logic similar to presumptuous philosopher and the idea that if Big Bang happened once it should also happen uncountably many times.)
Also, If only limited number of thing exist, there should be ontological force which prevent them popping from existence—and given that we exist we know that such popping is possible. The only thing which can limit the number of appearing is God. Bingo, we just got new proof of God’s existence!
But jokes asides, we obviously can’t prove factually existence of everything as it is unobservable, but we could use logical uncertainty to estimate probability of such claim. It is much more probable that everything possible exists, as there are three independent ways argue for it, and also if we assume the opposite, we have to invent some “limiting force” similar to God, which has low apriori probability.
Based on these my confidence in “everything possible exists” is 80-90 per cent.
You never compared or contrasted with any small/single universe theory.
On the same theme, you can’t say how much probability mass multiversal theories have, without knowing how much single universal theories have.
On the same theme, how can that be a meaningful number when you have never even thought about the rival theories?
Everything is based on assumptions. You are making an “anything will happen so long as it is not prevented” assumption. Many philosophers in the early modern period made an opposite assumption … that nothing can happen without Sufficient Reason.
Any reasoning is based on some assumptions and it is not a problem. We may list these assumptions and convert the into constrains of the model (with some probabilities).
Ok, lets try to prove the opposite thing.
Firstly, Kant in “Critiques of pure reason” explored these topics of the universe infinity in space in time and find that both propositions could be equally proved (finite and infinite), from which he concluded that the topics can’t be solved and is beyond human knowledge. However, Kant suggested on the margins one more proof of modal realism (I cite here by memory): “If a thing is possible in all aspects, there is no difference between it and real thing”.
The strongest argument against the existence of everything is non-randmoness of our experiences. If I am randomly selected from all possible minds, my observations should be very chaotic as most random minds are just random. There are several conter-arguments here: related either to chains of observer-moments converging to less random mind, or different measure of different minds, or that selection process of self-aware minds is a source of antirandomness, or that we in fact are random but can’t observe it, of that the internal structure of an observer is something like a convolutional neural net where randomness is concentrated to inputs and “order” to output. I will not elaborate these arguments here as it will be very long.
Another line of reasoning is connected with idea of actuality. In it, only me-now is real, and everything else is just possible. This line of reasoning is plausible, but it is even more weird than modal realism.
Then again, the idea of (Christian) God which creates only a few worlds. Improbable.
During last year EA forum, the following prove of the finitness of the universe was suggested:
“1) Finite means that available compute in the quantum theoretic sense in our future light cone is finite.
2) The Bekenstein bound says the information in a region is bounded proportional to area.
3) The universe’s expnasion is accelerating, so the there is a finite region of space that determines our future light cone.
4) Quantum mechanics is reversible, so the information of our future light cone is finite.
5) Only finite compute can be done given a finite information bound without cycling.”
But it is applicable only to our universe, but not to other universes.
There seems to be a common pattern where you start off with an assumption that mispredicts experience , and then make a further assumption to fix the situation. But that’s one step backwards, one step forwards. You end up with a more complex theory than one that takes one step forward, and just predicts experience.
It looks like that you think that modal realism is false and everything possible doesn’t exist. What is the argument which convinced you in it?
I haven’t said much about the object level issue. Im inclined to agree with the OP that anthropic probability doesn’t work. I haven’t seen you argue against small/single worlds except to quote a probability!
All reasoning is based on assumptions and it’s a problem, because it makes it hard to converge on beliefs, or ever settle questions.
There’s a partial solution, in that not all assumptions are equal , and not all numbers of assumptions are equal.
That’s a fairly traditional version of Occams Razor based on minimising the number, and maximising the likelihood of assumptions.
Umm..well, suggestion, not proof.
All arguments depend on assumptions ,and yours is no exception.
For one thing , you are assuming fairly strong realism about time. That’s not a feature of all theories, or even all multiversal theories. Tegmarks mathematical multiverse struggles to explain time as a subjective phenomenon.
Actually, I didn’t assume realism about time, but the language we use works this way. Popping into existence may relate to Boltzmann brains which don’t have time.
Boltzman brains that have some sort of ongoing experience of a stable universe are very problematical ,too.
The could form chains, like in dust theory or its mathematical formalism here: https://arxiv.org/abs/1712.01826
Prima facie, Boltzman brain theories don’t predict experience. People sometimes try to fix that problem by making additional assumptions about consciousnes, leveraging the fact that no one knows how consciousness works.
It may seem very natural to say “I” am a randomly chosen observer (from some proposed reference class). But keep in mind that is an assumption. PBA suggests that assumption is wrong. And if we reason from one consistent perspective such kind of assumptions are unnecessary.
Ok, let’s look at a real world example: “drivers in next lane are going faster” suggested by Bostrom. It is true from observer’s point of view but not true from the God’s view.
“The drivers in the next lane are going faster” is true both from a driver’s first-person view and from a god’s eye view. However, none of those two are self-locating probabilities. This is explained by PBA’s position on self-locating probabilities, by the link mentioned above.
The lane assignment can be regarded as an experiment. The lane with more vehicles assigned to it moves slower. Here, from a god’s eye view, if a random car is selected then the probability of it from the slow lane is higher. From a driver’s first-person view, “I” and the other drivers are in symmetrical positions in this lane assigning experiment. So the probability of me being in the slow lane is higher. According to PBA, both probabilities are valid. However, they are not the same concept, though they have the same value. (This point have been illustrated by Question 1 and Question 2 in the link above)
However, neither of them are self-locating probabilities in the anthropic context. Some anthropic reasoning suggests there is an innate reference class for indexicals like “I”. E.g. SSA assumes “I” can be considered a randomly chosen human from all humans. This requires both the first-person to identify “I” and a god’s eye view to do the choosing. It does not depend on any experiment. Compare this with the driver’s first-person view above, the reference class is all drivers on the road. It is defined by the lane assigning experiment. It does not even matter if other drivers are humans or not. They could be all pigs and they would still be in symmetrical positions with me. The PBA argues the self-locating probabilities are invalid. (This point has been demonstrated by Question 3 in the link above.)
Since we are discussing Nick Bostrom’s position, he made the explicit statement in “The Mysteries of Self-Locating Belief and Anthropic Reasoning” that an experiment is unnecessary in defining the reference class. We can always treat “I” as the result of an imaginary sampling process. This is in direct conflict with my PBA. According to PBA, anthropics is not an observation selection effect, just recognizing the perspective of reasoning.
Lastly, you are clearly interested in this topic. I just find the questions you raised have already been covered by the argument presented on my website. I can only recommend you give it a read. Because this question and answer model of communication is disproportionally effort heavy on my part. Cheers.