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.
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.