I maintain that it’s an unnatural distinction to draw—a universe that will be connected to ours in the future, or has been connected to ours in the past, isn’t empirically different from one that is and will always be disconnected from ours
Empirical: based on, concerned with, or verifiable by observation or experience rather than theory or pure logic.
A universe that is totally disconnected is unverifiable by observation and experience. It lies in the realm of pure logic. It leaves no empirical traces.
Granted, there are also some possible universes that are logically connected and yet leave no empirical traces. (One example of this is the “Heaven” hypothesis, which postulates a place which is totally unobservable at the present time. So our universe has an effect on Heaven-verse, creating a unidirectional causal link… but Heaven has no effect on us. It’s the same with your example—the past has a unidirectional causal link with various possible futures.)
So yes, I bite the thing you regard as a bullet. There are not necessarily any empirical differences. I still think that when the common person says “Reality”, they mean something closer to my definition—something with a causal interaction with you. That’s why people might say “heaven is real, despite the lack of evidence” or “Russel’s Teapot might be real, though it’s unlikely” but they never say “Harry Potter is real, despite the lack of evidence” or “Set theory is real, despite the lack of evidence”.
All of these things can be represented totally unobservable logical structures, but only the Heaven structure is proposed to interact with our universe—so only the Heaven structure is a hypothesis about reality. The rest are fantasy and mathematics.
(If you want empiricism, I will say that the most parsimonious hypothesis is strictly limited to choosing the smallest logical structure which explains all observable things.)
Edit:
Oh cool—you’ve made me realized that my definition of reality implies random events create a universe for each option (so a stochastic coin flip creates a “heads” universe and a “tails” universe, both “real” | real = “causal interaction in either direction”). I hadn’t explicitly recognized that yet. Thanks!
I think I’m actually fairly comfortable with that. However it does seem to run slightly contrary to layman use of “reality” and I like to keep my rigorized definitions of words as close as possible to the unrigorous layman’s usage. I might be returning with a slightly revised definition which tackles some of the weirdness surrounding unidirectional relationships. If I can’t find one, I bite the bullet and accept the divergence of my “reality” from layman’s “reality” via “universes with randomness have many real worlds, splitting for each random event”. Doesn’t seem like too harsh of a bullet though—laymen’s definitions aren’t always internally consistent and do sometimes collapse under rigorization. If I find that I can’t wiggle out of this, it does mean that I might have to think more about anthropics and slightly alter the way I conceptualize the relationship between my “utility” function and what I’ve been calling reality.
(I still think your ontology of “all tautologies are real” is even farther from laymen’s ontology and possibly makes morality go all funny for the reasons described in my top post on the topic. Not sure whether you think distance from laymen’s definitions is something worth minimizing, but figuring out how utility/morality works in your ontology is important)
I still think that when the common person says “Reality”, they mean something closer to my definition—something with a causal interaction with you. That’s why people might say “heaven is real, despite the lack of evidence” or “Russel’s Teapot might be real, though it’s unlikely” but they never say “Harry Potter is real, despite the lack of evidence” or “Set theory is real, despite the lack of evidence”.
I try not to say “reality”—I don’t think laypeople have an intuition about the case where we disagree—that is, regions that are causally disconnected (in the sense of the relativistic term of art—whose meaning apparently doesn’t align with your intuition?) from us, but can be reached by some zigzag chain of causal paths. In the Heaven case there’s a one-directional causal link, and in Russell’s teapot case there’s a regular causal connection. Do people have an intuition about whether things that have fallen into a black hole, or over the cosmological event horizon, are “still real”?
That said, on some level you’re right; I do feel that Bob is “more real” than Harry Potter. I think that’s just a function of Bob’s universe being more similar to my own though. If Carol in another universe has a magical cross-universe teleporter and is thinking about whether to visit our universe, it seems wrong to say she’s more real now if the decision she’s about to make is yes than if the decision is no. (And the notion that she’s already connected to our universe because she has the choice, even if she never actually visits our universe, feels equally suspect)
(Feel free to stop replying if I’m getting repetitive, and thanks for the discussion so far in any case)
I still think your ontology of “all tautologies are real” is even farther from laymen’s ontology and possibly makes morality go all funny for the reasons described in my top post on the topic.
I agree; I’ve never felt happy with the simulation argument in any form, and trying to chase through its more extreme implications was as much about hoping to find a contradiction as about exploring things that I thought were true. Like I’ve said, I’m hopeful that a good theory of anthropics will dissolve these questions.
Now, that confuses me. I thought your post was largely about defining reality. Isn’t the topic under discussion largely what the appropriate way to define reality is? Isn’t the very premise of platonic realism that all tautologies are real?
We often use words (soul, free will, etc) to define ideas that aren’t well defined. Sometimes, on rigorous inspection, those ideas turn out to be nonsensical. This leaves us with two options:
1) Discard the words altogether
2) Re-define the words so as to get as close as possible to the original meaning, while maintaining self-consistency. (see Eliezer’s posts on “free will” for an example of this which is carried out, I believe, successfully.).
I generally opt for (2) in the cases where the underlying concept being described as some sort of value and there is no other word that quite tackles it.
I maintain that “reality” is one of those words for which the underlying concept is valuable and un-described by any other word. I remain unsure of whether or not the laymen’s intuitive definition of “Reality” is logically consistent. I’ll continue trying to find a rigorous definition that completely captures the original intuition and nothing more. If I end up giving up I’ll have to opt for (2) or (1)...If, under the closest definition, probabilistic-many-world-splitting turns out to be the only “weird-to-normal-people” consequence of changing the definition then I’m okay with picking (2), since at least the practical consequences add up to normality.
I’d choose option (1) and abolish “reality” altogether, though, before I let it be turned into a synonym for “tautology”. That’s just too far from the original intuition to be a useful verbal label and we already have “tautology” anyhow. Plus, the practical consequences do not seem to add up to normality at all.
Empirical: based on, concerned with, or verifiable by observation or experience rather than theory or pure logic.
A universe that is totally disconnected is unverifiable by observation and experience. It lies in the realm of pure logic. It leaves no empirical traces.
Granted, there are also some possible universes that are logically connected and yet leave no empirical traces. (One example of this is the “Heaven” hypothesis, which postulates a place which is totally unobservable at the present time. So our universe has an effect on Heaven-verse, creating a unidirectional causal link… but Heaven has no effect on us. It’s the same with your example—the past has a unidirectional causal link with various possible futures.)
So yes, I bite the thing you regard as a bullet. There are not necessarily any empirical differences. I still think that when the common person says “Reality”, they mean something closer to my definition—something with a causal interaction with you. That’s why people might say “heaven is real, despite the lack of evidence” or “Russel’s Teapot might be real, though it’s unlikely” but they never say “Harry Potter is real, despite the lack of evidence” or “Set theory is real, despite the lack of evidence”.
All of these things can be represented totally unobservable logical structures, but only the Heaven structure is proposed to interact with our universe—so only the Heaven structure is a hypothesis about reality. The rest are fantasy and mathematics.
(If you want empiricism, I will say that the most parsimonious hypothesis is strictly limited to choosing the smallest logical structure which explains all observable things.)
Edit:
Oh cool—you’ve made me realized that my definition of reality implies random events create a universe for each option (so a stochastic coin flip creates a “heads” universe and a “tails” universe, both “real” | real = “causal interaction in either direction”). I hadn’t explicitly recognized that yet. Thanks!
I think I’m actually fairly comfortable with that. However it does seem to run slightly contrary to layman use of “reality” and I like to keep my rigorized definitions of words as close as possible to the unrigorous layman’s usage. I might be returning with a slightly revised definition which tackles some of the weirdness surrounding unidirectional relationships. If I can’t find one, I bite the bullet and accept the divergence of my “reality” from layman’s “reality” via “universes with randomness have many real worlds, splitting for each random event”. Doesn’t seem like too harsh of a bullet though—laymen’s definitions aren’t always internally consistent and do sometimes collapse under rigorization. If I find that I can’t wiggle out of this, it does mean that I might have to think more about anthropics and slightly alter the way I conceptualize the relationship between my “utility” function and what I’ve been calling reality.
(I still think your ontology of “all tautologies are real” is even farther from laymen’s ontology and possibly makes morality go all funny for the reasons described in my top post on the topic. Not sure whether you think distance from laymen’s definitions is something worth minimizing, but figuring out how utility/morality works in your ontology is important)
I try not to say “reality”—I don’t think laypeople have an intuition about the case where we disagree—that is, regions that are causally disconnected (in the sense of the relativistic term of art—whose meaning apparently doesn’t align with your intuition?) from us, but can be reached by some zigzag chain of causal paths. In the Heaven case there’s a one-directional causal link, and in Russell’s teapot case there’s a regular causal connection. Do people have an intuition about whether things that have fallen into a black hole, or over the cosmological event horizon, are “still real”?
That said, on some level you’re right; I do feel that Bob is “more real” than Harry Potter. I think that’s just a function of Bob’s universe being more similar to my own though. If Carol in another universe has a magical cross-universe teleporter and is thinking about whether to visit our universe, it seems wrong to say she’s more real now if the decision she’s about to make is yes than if the decision is no. (And the notion that she’s already connected to our universe because she has the choice, even if she never actually visits our universe, feels equally suspect)
(Feel free to stop replying if I’m getting repetitive, and thanks for the discussion so far in any case)
I agree; I’ve never felt happy with the simulation argument in any form, and trying to chase through its more extreme implications was as much about hoping to find a contradiction as about exploring things that I thought were true. Like I’ve said, I’m hopeful that a good theory of anthropics will dissolve these questions.
Now, that confuses me. I thought your post was largely about defining reality. Isn’t the topic under discussion largely what the appropriate way to define reality is? Isn’t the very premise of platonic realism that all tautologies are real?
Hmm, you’re right. Maybe I just object to “reality” because it implies a uniqueness that I don’t think is justified.
My philosophy on words is this:
We often use words (soul, free will, etc) to define ideas that aren’t well defined. Sometimes, on rigorous inspection, those ideas turn out to be nonsensical. This leaves us with two options:
1) Discard the words altogether
2) Re-define the words so as to get as close as possible to the original meaning, while maintaining self-consistency. (see Eliezer’s posts on “free will” for an example of this which is carried out, I believe, successfully.).
I generally opt for (2) in the cases where the underlying concept being described as some sort of value and there is no other word that quite tackles it.
I maintain that “reality” is one of those words for which the underlying concept is valuable and un-described by any other word. I remain unsure of whether or not the laymen’s intuitive definition of “Reality” is logically consistent. I’ll continue trying to find a rigorous definition that completely captures the original intuition and nothing more. If I end up giving up I’ll have to opt for (2) or (1)...If, under the closest definition, probabilistic-many-world-splitting turns out to be the only “weird-to-normal-people” consequence of changing the definition then I’m okay with picking (2), since at least the practical consequences add up to normality.
I’d choose option (1) and abolish “reality” altogether, though, before I let it be turned into a synonym for “tautology”. That’s just too far from the original intuition to be a useful verbal label and we already have “tautology” anyhow. Plus, the practical consequences do not seem to add up to normality at all.