I feel like this is just a really obnoxious argument about definitions.
I especially feel like this is a really obnoxious argument about definitions when the wiki article quotes things like:
“Take the supposed illusion of change. This must mean that something, X, appears to change when in fact it does not change at all. That may be true about X; but how could the illusion occur unless there were change somewhere? If there is no change in X, there must be a change in the deluded mind that contemplates X. The illusion of change is actually a changing illusion. Thus the illusion of change implies the reality of some change. Change, therefore, is invincible in its stubbornness; for no one can deny the appearance of change.”
So, to taboo a bunch of words, and to try and state my take on the actual issue as I understand it (including some snark):
B theory: Let there be this thing called spacetime which encodes all moments of time (past,present, future) and space (i.e., the universe). The phenomenal experience of existence is akin to tracking a very particular slice of spacetime move along at the speed that time inches forward, as observed by me.
A theory: My mind is the fundamental metaphysical object, and moments of “time” can only be oriented with respect to my immediate phenomenal experience of reality. Trying to say something about a grand catalog of time (including the future) robs me of this phenomenal experience because I know what I’m feeling, and I’m feeling the phenomenal experience of existing right now, dammit! Point to that on your fancy spacetime chart!
Read this way, I suppose the most succinct objection of the A-theorist is: “If all of spacetime exists, all reference frames are equivalent, etc. etc., why am I, in this moment, existing right now?” To which, I imagine, a B-theorist would respond by saying, “Because you’re right here,” and would then point to their location on the spacetime chart.
But this isn’t actually an argument about what time is like. It’s an argument about how whether or not we should privilege the phenomenal experience of existing—of experiencing the now. That is, does me experiencing life right at this moment mean that this moment is special?
I suppose I can see why people that aren’t computationalists would be bothered by the B theory, because it does rob you of that special-ness.
After reading your comment, I agree that this is probably just a semantic question with no real meaning. This is interesting, because I completely failed to realize this myself and instead constructed an elaborate rationalization for why the distinction exists.
While reading the wikipedia page, I found myself interpreting meaning into these two viewpoints that were probably never intended to be there. I am mentioning this both because I find it interesting that I reinterpreted both theories to be consistent with my own believes without realizing it, and because I would like to see what others have to say about those reinterpretations. I should point out that I am currently really tired and only skimmed the article, so that probably wouldn’t have happened under ordinary circumstances, but I still think that this is interesting because it shows the inferential gap at work:
I am a computationalist, and as such the distinction between the two theories was pretty meaningless to me at first. However, I reinterpreted the two theories in ways that were almost certainly never intended, so that they did make sense to me as a reasonable distinction:
the A theory corresponds to living in a universe where the laws of physics progress like in a simple physical simulation, with a global variable to measure time and rules for how to incrementally get from one state to the next. I assume for the purpose of this theory that quantum-mechanical and relativistic effects that view time non-linearly can be abstracted in some way so that a single, universal time value suffices regardless. I interpreted it like this because I thought the crux of the theory was having a central anchor point for past and future.
the B theory corresponds to living in a highly abstracted simulation where many things are only computed when they become relevant for whatever the focus of the simulation is on. For instance, say the focus is on accurately modelling sapient life, then the exact atomic composition of a random rock is largely irrelevant and is not computed at first. However, when the rock is analyzed by a scientist, this information does become relevant. The simulation now checks what level of detail is required (i.e. how precise the measuring is) and backpropagates causal chains on how the rock came to be, in order to update the information about the rock’s structure. In this way, unnecessary computations are avoided. I interpreted it like this because I thought the crux of the theory was the causal structure between events.
In essence, the A theory would correspond to a mindless, brute-force computation, while the B theory implies a deliberate, efficient computation that follows some explicit goal. This is nowhere near what the A and B theory actually seem to say now that I have read the article in more detail. In fact, the philosophical/moral implications are almost reversed under some viewpoints. I find it very interesting that this is the first thing that came to mind when I read it.
I probably should have written “presentism” and “eternalism” instead of “A-theory” and “B-theory”. Does the dispute between presentism and eternalism also seem to you to have no real meaning?
It’s worse than your typical verbal dispute IMO, because in this case the two verbal conventions could live happily side by side, without over-complicating our communications. All we need to do is be careful with tensed verbs. I haven’t argued for this. But try it out for yourself, and see if it works. Here is a blog post I read that I think supports my view, even though the author winds up in a different post thinking there is a genuine puzzle.
Edit: Luke_A_Somers seems to have beaten me to it. Further edit: A-theory, on some ways of fleshing it out at least, may be richer than presentism.
The dispute between the A-theory and the B-theory is not a dispute about whether, say, “A-series” talk is valid. Everyone agrees that A-series talk (past, present, future) and B-series talk (before, during, after) are both valid.
The dispute is about which kind of talk is more “fundamental”. In particular, if A-series talk is fundamental, then, it seems, there must be an objective fact about which time is “present”, and this fact is independent of the time at which the question is asked. If the A-theory is true, then asking which time is “present” is like asking “Who is torekp” rather than “Who am I”, because the answer to the first question doesn’t depend on who is asking.
To the make the analogy tighter, asking which time is “present” is like asking “Who is torekp?” in a world where the name “torekp” rotates through the population in a systematic way. Yes, the answer is different at different times, but the answer changes without regard to who is doing the asking. Similarly (on the A-theory), the answer to which time is present changes (in some elusive sense), but the change happens without regard to when the question is asked.
That’s a great explanation (the non-relative, non-indexical now, and “who is” analogy—not the “fundamental” talk, which just makes me cringe). But that’s A-theory, not presentism, which is being explained, right? This paper claims there’s a distinction, at least in that one can be a presentist without endorsing A-theory.
But that’s A-theory, not presentism, which is being explained, right? This paper claims there’s a distinction
Yes. One can certainly be an A-theorist without being a presentist. Some people really have subscribed to so-called “moving spotlight” theories. (Hermann Weyl was an example.)
I’m less convinced that anyone was ever a presentist but not an A-theorist. The paper you cite doesn’t convince me for at least the following reasons.
First, the paper doesn’t even argue that any non-A-theorist presentists have ever actually existed. Rather, the paper attempts to show that such a theory is, as it were, technically possible.
Second, I don’t buy that the paper succeeds even at this. The author constructs the theory in Section 4. But the constructions essentially depends on a loophole: A-theories must posit A-properties, he says, but existence is not a property. Then, in Section 5.3, he deals with what seems to me to be the obvious reply. He allows that maybe A-theories only require A-facts, and not necessarily A-properties. If existence is a fact, then his construction fails. His reply is that “it is still possible to be a presentist without being an A-theorist: we need simply deny the existence of facts. … If there are no facts at all then there are no existence facts. … This is not an unreasonable view. There are metaphysical systems that do not posit facts—versions of substance theory, bundle theory, and so on.”
I find this unconvincing. I don’t know enough about these other theories to know how they get by without facts. But I suspect that they introduce some kind of things, call them faks, that do the work of facts. I suspect that the A-theory could just as well be held to require only that there are A-faks.
Does the argument over interpretations of QM also seem like just semantics to you?
For example, when Eliezer advocates for MWI over Copenhagen, is he mistaken in thinking that he is engaged in a substantive argument rather than a merely semantic one?
No, the distinction between MWI and Copenhagen would have actual physical consequences. For instance, if you die in the Copenhagen interpretation, you die in real life. If you die in MWI, there is still a copy of you elsewhere that didn’t die. MWI allows for quantum immortality.
The distinction between presentism and eternalism, as far as I can tell, does not imply any difference in the way the world works.
No, the distinction between MWI and Copenhagen would have actual physical consequences. For instance, if you die in the Copenhagen interpretation, you die in real life. If you die in MWI, there is still a copy of you elsewhere that didn’t die. MWI allows for quantum immortality.
Analogously, under the A-theory, dying-you does not exist anywhere in spacetime. The only “you” that exists is the present living you.
Under the B-theory, dying-you does exist right now (assuming that you’ll eventually die). It just doesn’t exist (I hope) at this point in spacetime, where “this point” is the point at which you are reading this sentence. When you die in the A-theory, there is not a copy of you elsewhen that isn’t dying. The B-theory, in contrast, allows for a kind of Spinoza-style timeless immortality. It will always be the case that you are living at this moment.
(As usual in this thread, I’m treating “A-theory” and “presentism” as being broadly synonymous.)
If you think that other points of spacetime exist, then you’re essentially a B-theorist. If you want to be an A-theorist nonetheless, you’ll have to add some kind of additional structure to your world model, just as single-world QM needs to add a “world eater” to many-worlds QM.
I’m not entirely sure what you mean by ‘Spinoza-style’, but I get the gist of it and find this analogy interesting. Could you explain what you mean by Spinoza-style? My knowledge of ancient philosophers is a little rusty.
That post discusses one interpretation of Spinoza’s notion of immortality. The basic idea is that the entire universe exists in a timeless sense “from the standpoint of eternity”, and the entire universe is the way it is necessarily. Hence, every part of the universe, including ourselves, exists eternally in the universe. Because the universe is necessarily the way it is, no part of it can ever not exist.
The original distinction. My reconstruction is what I came up with in an attempt to interpret meaning into it.
I agree that my reconstruction is not at all accurate. It’s just something that occurred to me while reading it and I found it fascinating enough to write about it. In fact, I even said that in my original post.
The main objection to B/eternalism is that it doesn’t explain change, as either reality .or illusion....as the WP article says.
B theory: Let there be this thing called spacetime which encodes all moments of time (past,present, future) and space (i.e., the universe). The phenomenal experience of existence is akin to tracking a very particular slice of spacetime move along at the speed that time inches forward, as observed by me.A theory:
The problem is how the tracking works. If you were allowed some sort of moving cursor, that would easy. But you’re not.
In this post, I use the words “A-theory” and “B-theory” as a sloppy shorthand for “presentism” and “eternalism”, respectively. The point is that these are theories of ontology (“Does the future exist?”), and not just theories about how we should talk about time. This shouldn’t seem like merely a semantic or vacuous dispute unless, as in certain caricatures of logical positivism, you think that the question of whether X exists is always just the question of whether X can be directly experienced.
I feel like this is just a really obnoxious argument about definitions.
I especially feel like this is a really obnoxious argument about definitions when the wiki article quotes things like:
So, to taboo a bunch of words, and to try and state my take on the actual issue as I understand it (including some snark):
B theory: Let there be this thing called spacetime which encodes all moments of time (past,present, future) and space (i.e., the universe). The phenomenal experience of existence is akin to tracking a very particular slice of spacetime move along at the speed that time inches forward, as observed by me.
A theory: My mind is the fundamental metaphysical object, and moments of “time” can only be oriented with respect to my immediate phenomenal experience of reality. Trying to say something about a grand catalog of time (including the future) robs me of this phenomenal experience because I know what I’m feeling, and I’m feeling the phenomenal experience of existing right now, dammit! Point to that on your fancy spacetime chart!
Read this way, I suppose the most succinct objection of the A-theorist is: “If all of spacetime exists, all reference frames are equivalent, etc. etc., why am I, in this moment, existing right now?” To which, I imagine, a B-theorist would respond by saying, “Because you’re right here,” and would then point to their location on the spacetime chart.
But this isn’t actually an argument about what time is like. It’s an argument about how whether or not we should privilege the phenomenal experience of existing—of experiencing the now. That is, does me experiencing life right at this moment mean that this moment is special?
I suppose I can see why people that aren’t computationalists would be bothered by the B theory, because it does rob you of that special-ness.
After reading your comment, I agree that this is probably just a semantic question with no real meaning. This is interesting, because I completely failed to realize this myself and instead constructed an elaborate rationalization for why the distinction exists.
While reading the wikipedia page, I found myself interpreting meaning into these two viewpoints that were probably never intended to be there. I am mentioning this both because I find it interesting that I reinterpreted both theories to be consistent with my own believes without realizing it, and because I would like to see what others have to say about those reinterpretations. I should point out that I am currently really tired and only skimmed the article, so that probably wouldn’t have happened under ordinary circumstances, but I still think that this is interesting because it shows the inferential gap at work:
I am a computationalist, and as such the distinction between the two theories was pretty meaningless to me at first. However, I reinterpreted the two theories in ways that were almost certainly never intended, so that they did make sense to me as a reasonable distinction:
the A theory corresponds to living in a universe where the laws of physics progress like in a simple physical simulation, with a global variable to measure time and rules for how to incrementally get from one state to the next. I assume for the purpose of this theory that quantum-mechanical and relativistic effects that view time non-linearly can be abstracted in some way so that a single, universal time value suffices regardless. I interpreted it like this because I thought the crux of the theory was having a central anchor point for past and future.
the B theory corresponds to living in a highly abstracted simulation where many things are only computed when they become relevant for whatever the focus of the simulation is on. For instance, say the focus is on accurately modelling sapient life, then the exact atomic composition of a random rock is largely irrelevant and is not computed at first. However, when the rock is analyzed by a scientist, this information does become relevant. The simulation now checks what level of detail is required (i.e. how precise the measuring is) and backpropagates causal chains on how the rock came to be, in order to update the information about the rock’s structure. In this way, unnecessary computations are avoided. I interpreted it like this because I thought the crux of the theory was the causal structure between events.
In essence, the A theory would correspond to a mindless, brute-force computation, while the B theory implies a deliberate, efficient computation that follows some explicit goal. This is nowhere near what the A and B theory actually seem to say now that I have read the article in more detail. In fact, the philosophical/moral implications are almost reversed under some viewpoints. I find it very interesting that this is the first thing that came to mind when I read it.
I probably should have written “presentism” and “eternalism” instead of “A-theory” and “B-theory”. Does the dispute between presentism and eternalism also seem to you to have no real meaning?
It’s worse than your typical verbal dispute IMO, because in this case the two verbal conventions could live happily side by side, without over-complicating our communications. All we need to do is be careful with tensed verbs. I haven’t argued for this. But try it out for yourself, and see if it works. Here is a blog post I read that I think supports my view, even though the author winds up in a different post thinking there is a genuine puzzle.
Edit: Luke_A_Somers seems to have beaten me to it. Further edit: A-theory, on some ways of fleshing it out at least, may be richer than presentism.
The dispute between the A-theory and the B-theory is not a dispute about whether, say, “A-series” talk is valid. Everyone agrees that A-series talk (past, present, future) and B-series talk (before, during, after) are both valid.
The dispute is about which kind of talk is more “fundamental”. In particular, if A-series talk is fundamental, then, it seems, there must be an objective fact about which time is “present”, and this fact is independent of the time at which the question is asked. If the A-theory is true, then asking which time is “present” is like asking “Who is torekp” rather than “Who am I”, because the answer to the first question doesn’t depend on who is asking.
To the make the analogy tighter, asking which time is “present” is like asking “Who is torekp?” in a world where the name “torekp” rotates through the population in a systematic way. Yes, the answer is different at different times, but the answer changes without regard to who is doing the asking. Similarly (on the A-theory), the answer to which time is present changes (in some elusive sense), but the change happens without regard to when the question is asked.
That’s a great explanation (the non-relative, non-indexical now, and “who is” analogy—not the “fundamental” talk, which just makes me cringe). But that’s A-theory, not presentism, which is being explained, right? This paper claims there’s a distinction, at least in that one can be a presentist without endorsing A-theory.
Yes. One can certainly be an A-theorist without being a presentist. Some people really have subscribed to so-called “moving spotlight” theories. (Hermann Weyl was an example.)
I’m less convinced that anyone was ever a presentist but not an A-theorist. The paper you cite doesn’t convince me for at least the following reasons.
First, the paper doesn’t even argue that any non-A-theorist presentists have ever actually existed. Rather, the paper attempts to show that such a theory is, as it were, technically possible.
Second, I don’t buy that the paper succeeds even at this. The author constructs the theory in Section 4. But the constructions essentially depends on a loophole: A-theories must posit A-properties, he says, but existence is not a property. Then, in Section 5.3, he deals with what seems to me to be the obvious reply. He allows that maybe A-theories only require A-facts, and not necessarily A-properties. If existence is a fact, then his construction fails. His reply is that “it is still possible to be a presentist without being an A-theorist: we need simply deny the existence of facts. … If there are no facts at all then there are no existence facts. … This is not an unreasonable view. There are metaphysical systems that do not posit facts—versions of substance theory, bundle theory, and so on.”
I find this unconvincing. I don’t know enough about these other theories to know how they get by without facts. But I suspect that they introduce some kind of things, call them faks, that do the work of facts. I suspect that the A-theory could just as well be held to require only that there are A-faks.
OK, thanks
The meanings are much clearer now.
However, I still think that it is an argument about semantics and calef’s argument still holds.
Does the argument over interpretations of QM also seem like just semantics to you?
For example, when Eliezer advocates for MWI over Copenhagen, is he mistaken in thinking that he is engaged in a substantive argument rather than a merely semantic one?
No, the distinction between MWI and Copenhagen would have actual physical consequences. For instance, if you die in the Copenhagen interpretation, you die in real life. If you die in MWI, there is still a copy of you elsewhere that didn’t die. MWI allows for quantum immortality.
The distinction between presentism and eternalism, as far as I can tell, does not imply any difference in the way the world works.
Analogously, under the A-theory, dying-you does not exist anywhere in spacetime. The only “you” that exists is the present living you.
Under the B-theory, dying-you does exist right now (assuming that you’ll eventually die). It just doesn’t exist (I hope) at this point in spacetime, where “this point” is the point at which you are reading this sentence. When you die in the A-theory, there is not a copy of you elsewhen that isn’t dying. The B-theory, in contrast, allows for a kind of Spinoza-style timeless immortality. It will always be the case that you are living at this moment.
(As usual in this thread, I’m treating “A-theory” and “presentism” as being broadly synonymous.)
If you think that other points of spacetime exist, then you’re essentially a B-theorist. If you want to be an A-theorist nonetheless, you’ll have to add some kind of additional structure to your world model, just as single-world QM needs to add a “world eater” to many-worlds QM.
I’m not entirely sure what you mean by ‘Spinoza-style’, but I get the gist of it and find this analogy interesting. Could you explain what you mean by Spinoza-style? My knowledge of ancient philosophers is a little rusty.
Sorry just to throw a link at you, but here is a link :)
http://kvond.wordpress.com/2008/07/03/spinoza-on-the-immortality-of-the-soul/
That post discusses one interpretation of Spinoza’s notion of immortality. The basic idea is that the entire universe exists in a timeless sense “from the standpoint of eternity”, and the entire universe is the way it is necessarily. Hence, every part of the universe, including ourselves, exists eternally in the universe. Because the universe is necessarily the way it is, no part of it can ever not exist.
You mean the original distinction, or your computationalist reconstruction? (Which is not at all accurate in my view)
The original distinction. My reconstruction is what I came up with in an attempt to interpret meaning into it.
I agree that my reconstruction is not at all accurate. It’s just something that occurred to me while reading it and I found it fascinating enough to write about it. In fact, I even said that in my original post.
The main objection to B/eternalism is that it doesn’t explain change, as either reality .or illusion....as the WP article says.
The problem is how the tracking works. If you were allowed some sort of moving cursor, that would easy. But you’re not.
In this post, I use the words “A-theory” and “B-theory” as a sloppy shorthand for “presentism” and “eternalism”, respectively. The point is that these are theories of ontology (“Does the future exist?”), and not just theories about how we should talk about time. This shouldn’t seem like merely a semantic or vacuous dispute unless, as in certain caricatures of logical positivism, you think that the question of whether X exists is always just the question of whether X can be directly experienced.
(I’ve added this as a footnote to the post.)