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Modal logic and free will. Keith, Bob, Swartz, Dave, Tim: a bunch of guys.

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Posted

This is on the fly because David is insatiable.

More details will come soon, but we intend to continue the extended discussion that's was going on here over the past several years, relating to free will, the nature of time, and the particular thoughts of Norman Swartz. The most recent iteration is here: http://www.galilean-library.org/site/index.php/topic/3481-the-logical-structure-of-time-travel/

As usual, David and I got back into the discussion in chat, and long story short it's all happening again.

The debate so far has centered on one of Swartz's arguments. Dave being its advocate will no doubt go into some depth, but it has to do with the ideas of neccessity and contingency in modal logic. In plain english, I think I can do the argument justice in plainish english thus:

In eternalism, a particular outcome for a present choice exists in the future. Given this, we might say that the option chosen must be the one that leads to this outcome, since it axiomatically can't be changed. Swartz would say that this commits a modal fallacy, improperly classifying the choice event as modally necessary, when in fact it should be rightly considered a modally contingent event. Since a modally contingent event is one that could have been otherwise, we should say that there is nothing here that impedes libertarian free will, which demands that one be able to chose from multiple different options.

My (current) counterargument centers on making a distinction between kinds of 'possible' that I feel are being treated a bit cavalier here. Succinctly, I want to say that while I understand that an event being modally necessary would kill free will, an events being modally contingent is not on its own SUFFICIENT to say that free will may obtain in that event. I use the example of a prisoner held firmly captive: he may only do one thing at this time, which is to remain chained to the wall (also his name is Keith). This fact about what keith does is modally contingent, but we would not say that he has the option to choose to do something else.

I want if possible to place as much focus on that argument as possible here. I feel there is a conflation of terminology going on that permits swartz's argument to make sense. What I want to say is that even though his modal logic is correct, it concludes a sense of 'possible' does not translate to what is required from 'possible' when we speak of the options available to us when we make a choice. I want to be able say that it at least makes sense to speak of an agent performing an action, having the fact of that be rightly identified as a modally contingent fact, one which could have been otherwise, and yet still maintaining that the agent had no choice in the matter. Keiths scenario is a demonstration of ONE way this position might be held (it's hard to deny either that the fact of keiths incarceration could have been otherwise, or that he has any choice in the matter), but physical constraint is not the point of this thought exercise. Rather, I mean to show that the demonstration of modal contingency is insufficient to permit free will in all cases, and if that is the case, holding that an agents action, though contingent, is not free, does not commit the modal fallacy.

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Posted (edited)

In modal logic, a proposition is said to be “possibly true” if and only if it is not necessarily false. Thus, for instance, it is possibly true that I flap my arms and fly to the moon. The reason that this is possibly true, is that flapping my arms and flying to the moon entails no logical contradiction. By contrast, it’s not possibly true that 2+2=5, or that there are married bachelors. So in modal logic, possibly true statements can encompass states of affairs that are physically impossible. And this (almost) is where Keith resides. I say “almost” because his plight is not quite as dire as the case of someone trying to flap his wings and fly to the moon. One cannot envision, under any circumstances given the physical makeup of our world, anyone flapping his wings and flying to the moon. One can, barely, visualize Keith (somehow) escaping his chains by some method.

Be that as it may, and with the best will in the world not to do an injustice to your argument (which you have in the past claimed that I have done), I say in all earnestness that I fail to see how Keith applies by analogy to propositions about future contingents.

What is at issue here? I take it you are suggesting as follows: on the assumption of eternalism (that the future exists, along with the present and past), then the future is fixed. It is just as fixed as the past. There is nothing we can do about it. We can’t change the future, anymore than we can change the past.

I take you to be using Keith as a metaphor for being chained, so to say, to the wall of time. You say you agree that if future acts exist, then propositions about them now are contingently true, but like Keith, the doers of the acts are in a kind of metaphysical lockdown and can’t genuinely do, other than what they do. If this is not your argument, please correct me.

Now, to be clear, the modal fallacy goes like this: If today it’s true that tomorrow there will be a sea battle, then tomorrow there MUST be a sea battle, and no one can do anything about it. So we have no free will.

The fallacy, as previously discussed, lies in applying the concept of necessity to the consequent of the antecedent alone. In the sea battle case, the corrected argument is: IT HAS TO BE THE CASE THAT (if it’s true today that tomorrow there will be a sea battle, then tomorrow there WILL [Not must!] be a sea battle.) That is, the necessity lies in the joint relation of antecedent and consequent. It’s not that there MUST be a sea battle tomorrow; but rather that, if there IS a sea battle tomorrow, then it must be the case today that the proposition “there will be a sea battle tomorrow” is a true proposition. Of course, properly understood, this means that the actors have full free will. They either may, or may not, undertake a sea battle; if they undertake a sea battle tomorrow, there will be a true statement today that tomorrow they will undertake a sea battle. And if they DON’T undertake a sea battle, it will be true today that tomorrow they WON’T undertake such a battle.

Now, before going on, I just want to know if you AGREE with my above analysis. Because I understand the sea battle analysis skirts the plight of Keith entirely; I just want to make sure we’re on the same page. To put it another way: Do you agree that the navies under discussion have free will?

Edited by davidm

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Posted

We're not on the same page, for two reasons: First, since you asked, I don't agree that your take on the sea battle vindicates free will. Second, I am NOT trying to draw an analogy between keiths physical impossibility and the impossibility of bob saying ass (I'll post that comic again in a bit). At least, I'm not trying to do that directly.

What I am getting at is that when we want to populate a list of an agents genuinely open options, we have special requirements. I feel that that list is being populated with "possibilities" that do not satisfy those requirements, simply because we have demonstrated that one of the options is not modally necessary. The only reason I have Keith as a prisoner is to reduce the list of his genuinely available options to one, for rhetorical purposes. It's just so that when I ask "does keith have more than one option" you can't answer "yes he does - he may not be able to go to hawaii tomorrow, but he can choose which corner of the cell to sit in". Remember, free will can obtain if there is any number of options on his 'genuinely choosable' list other than one. So, I feel you're not with me when you talk about physical restraint.

The real point is this: that it CAN make sense to say "it is not modally neccessary that (option 2)" and that therefore "option 2 is possible" , while still maintaining that option 2 is not a genuinely open alternative - in Keiths case, because of physical constraint, but in bobs case, because of something else. What that something else is is problematic, and I think that's where you want to go with this, but that's not where we are yet.

I think both cases are unified, not by some analogy with physical constraint ("chained to the wall of time", which just sounds like the physical determinism we both moved past ages ago), but with an analysis of probability. An 'option' with zero probability should be rightly said to be not genuinely open, and both Keiths and Bobs other options must be said to have zero probability.

I'm suggesting that saying "bob must say pancakes, saying ass is impossible" does not commit the modal fallacy, because it doesn't use "must" and "possible" in the same way that the modal fallacy does.

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Posted

We're not on the same page, for two reasons: First, since you asked, I don't agree that your take on the sea battle vindicates free will.

In that case, I suggest we focus entirely on Aristotle's sea battle, and forget all about Bob and pancakes, and Keith chained to the wall and all the rest. It'll make things much simpler, since all the rest really is just the sea battle stated in different terms. Why don't your agree that my take on the sea battle vindicates free will? Because the sea battle "no-free-will" argument really is just a classic modal fallacy, which Aristotle did not recognize since modal logic had not yet been discovered/invented.

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Posted (edited)

Actually, maybe we should do this differently, though in the end it may make no difference. I think we just have two different intuitions about this stuff. The key difference is that mine is right and yours is wrong. :)

To avoid rehashing a lot of ground, you are a presentist and think only presentism can accommodate free will. You do not think eternalism can do that. And so even if you accept the logical analysis behind the modal fallacy, you think something is missing; that identifying the fallacy is not sufficient to establish free will. Something is missing, I think you believe, because eternalism says the future is FIXED, and cannot be changed; long before I am born I will do x, y, and z in the future, and so I have no GENUINE options to do other than what I will do.

And that is where we diverge, I think, and I’m not sure I will ever convince you of why this intuition of yours is erroneous.

It’s the same divergence we run into in discussing time travel into the past. I can make it as simple as possible; we don’t need to discuss Keith in chains, or Bob saying pancakes, or Tim going back and time and trying to kill his grandfather, as we did in the previous thread.

Suppose I go back in time to Sept. 9, 1958. I pick that date because I think it’s the date Stephen King has his character return to in his new novel, the premise of which is someone travels to the past to try to prevent the assassination of JFK. King quickly botches up the logic of time travel, but that’s OK because if he didn’t, he would have no story.

Suppose I go back in time to Sept. 9, 1958, and pick up a rock and throw it into the river. That’s all, nothing dramatic. Then I return to the time from which I came.

What did I do in the past? Did I change the past?

Many people assume that the very act of traveling to the past changes it. But this is wrong. It’s logically unsupported. It even bears the name of a fallacy: The second-time around fallacy. The past happens, and then someone comes back and changes it. So the past happens a second time, with a change.

But no. There always was, and always will be, a single Sept. 9, 1958. If you go back to the past and throw a rock into the river, then that is the thing that a future version of you did, before you were ever born. So before you were ever born, a future “you” threw a rock into a river in the past. So if you go back to the past and throw a rock in the river, then that is just exactly what you did before you were born. If you go back into the past and DON’T throw the rock in the river, then before you were ever born you DIDN’T throw the rock in the river. If in fact you pass your life and NEVER go back to Sept. 9, 1958, then even before you were born, you were NEVER in the past. I wonder if you will see? You can’t change the past! But, this doesn’t mean you don’t have free will! As I have repeatedly tried to show, free will is not about CHANGING the past, present or future. It is about making the past, present and future BE, what they were, are, and will be.

This doesn’t mean you can’t do what you want in the past. You CAN do what you want in the past. It’s just that, WHATEVER you do in the past, will be whatever you did before you were born; and whatever you did in the past, will be described by a true statement. When you talk about, as you have, going back and CHANGING the past, what you are asking for is not free will, which you already have, but a DO-OVER, which really means you want to violate the Law of Non-Contradiction: You want to throw a rock, and not throw a rock, in the past at the same time. You can’t do that, but not being able to violate the Law of Non-Contradiction does not mean you lack free will. No rational account of free will demands a violation of the laws of logic.

Edited by davidm

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Posted (edited)

Let me put it yet another way: I have given you three clear choices: Go back to the past and throw a rock in the river. Go back to the past and don't throw a rock in the river. Never go back to the past. You can choose any of the three -- among many other possibilities! Those are GENUINE OPTIONS.

It's just that -- again -- whatever you do, freely, will have been done before you were born. YOU did it; you could have done otherwise; but you did what you did. And so it goes. No lack of free will.

What you keep asking for is a genuine option to undo what you did -- a do-over. You don't get a do-over in any kind of time travel, including travel into the future that we normally do. From moment to moment you do things. And those are the things you do. You could have done different. But, you didn't. And you don't get a do-over.

Edited by davidm

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Posted (edited)

The problem with that is that what I ask for from free will does NOT violate any logical laws if presentism is true. You say I shouldn't "ask" to be able to violate the laws of logic, but that's actually the reverse of what I'm doing. I'm starting with a concept of free will, and analysing its feasability under different concepts of time. It turns out it would violate logic under eternalism, but not presentism.

Now, a great many people, finding eternalism probable, are forced to deny the existance of libertarian free will. That is probably the most common position among both scientists and philosophers who engage with this issue. The other camp finds the support for eternalism too weak to justify abandoning the idea that we have libertarian free will, and therefore conclude that either we should be agnostic about the issue, like Massimo Pigliucci or that the standard idea of eternalism must be somehow flawed. Acting like I am doing something straightforwardly stupid by framing the debate in this way makes you the odd one out.

Swartz's idea, that BOTH the standard conceptions of eternalism and libertarian free will can be reconciled, is VERY much the outside opinion here. I don't want to make an argument to majority or anything, but you say "No rational account of free will demands a violation of the laws of logic" where the implied irrational account of free will is the textbook libertarian free will I espouse, and 'violating the laws of logic' is what everyone and his dog thinks would happen if it and eternalism existed in the same universe.

What you are saying with the rest of your analysis is simply compatibilism. You are espousing bog standard compatibilist free will, but then claiming that it fulfills the requirements of libertarian free will. It doesn't. Swartz thinks it does, and makes that case by claiming that to say otherwise is a modal fallacy. That't the argument I'm trying to address, but you keep wanting to discuss other things.

I mean just look at what you've just argued. Your post is just an account of compatibilist free will, and then you tack on a few assertions about the requirement of genuine options being fulfilled, but that only works if you already accept swartz's argument! You want me to 'see' something here, but I'm afraid I understand perfectly well. I can see that what you say would be true, if it were really the case that incompatibilism makes a modal fallacy. Unfortunately that's what I take issue with, and the thing that most of my argumentation has been directed at.

Incompatibilism does not make a modal fallacy. It looks like it would, but that relies on a false equivalence between different senses of 'possible'. Keith unfolds those senses and puts them in proper order. It's impossible for Keith to leave the wall, and impossible for bob to say ass. Either both of these are modal fallacies, or neither is. I know that Keiths 'impossible' is due to physical constraint, and bobs 'impossible' isn't, but the kicker here is that if you agree that it is 'impossible' for Keith to leave the wall, I will accuse you of making the modal fallacy. Do you agree that it is impossible?

Actually, lets have a look at this 'impossible' here. Is it impossible for Keith to leave the wall? What happens if we start with the assertion "Keith MUST stay chained to the wall. Is it modally necessary that Keith stay on the wall? Clearly not. It's contingent on lots of things. So I can say that this commits the modal fallacy. We shouldn't say that Keith 'must' stay on the wall. Yet he clearly doesn't have free will. What happened? This: the sense of 'must' used in modal logic is not the same as used when we are thinking about free will. The modal fallacy is irrelevant to this kind of analysis.

Edited by Timothy

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Posted

Well, again, if you insist on bringing Keith, Bob, et al back into this, that’s fine, and I’ll address it, but I’m trying to keep things as simple as possible.

Libertarian free will means that one has genuine options and could have done other than what he did; and it means that one could even act contrary to one’s nature or impulses (one is not doing stuff for subconscious reasons as opposed to free choice). I don’t know if in reality we have that sort of free will; but what I am saying is that no account of the sort that we are discussing in this thread destroys libertarian free will.

Just focus on my time travel scenario. For simplicity’s sake, let’s winnow it down to two options. You go back to the past, to Sept. 9, 1958, and a rock is in the road. You will either leave the rock on the road, or throw it into the river. The choices are mutually exclusive and jointly exhaustive. They are GENUINE OPTIONS. You give no reason to believe they aren’t. Now I’m saying that IF you throw the rock into the river, then that is what you did before you were born. And so it is what you will do after you are born, when you grow up and then travel to the past. It’s not that you HAVE to do it, but you DID do it. And, since there is only one past, only ONE Sept. 9, 1958, you don’t get a do-over. And the point is, if you do OTHERWISE – if you leave the rock in the road – then leave the rock in the road is what you did before you were born, and what you will do when you grow up and travel to the past. So you can do one or the other, but you can’t escape the fact that what you do or don’t do, will be what you did or didn’t do even before you were born. Now, show me why you don’t have free will, in the above scenario. I maintain that what you are asking for is a do-over, the ability to both throw and not throw the rock, and this is inadmissible. But it’s also inadmissible in the mundane time travel that we all do, one second per second into the future. If tomorrow you are confronted with the option of throwing or not throwing a rock into the river, you either will or wont’ do it. You have a genuine choice, but no do-over.

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Posted

My problem is that I feel the terminology you are using to describe the situation is inappropriate. What you have again done is described free will and eternalism exactly how a compatibilist does, while asserting baselessly that it is not compatibilist but libertarian free will that you are describing. You can SAY 'genuine options' as much as you like but that doesn't make it true.

Or more to the point, there is a sense, possibly an important sense, in which your time traveller does make a genuine choice. After all, we are not suggesting he has been forced to throw the rock. No-one has a gun to his head, and in this case at least we aren't making the case that physical determinism 'forces' him. So the determination 'comes from' him, and in that sense he 'could have' done otherwise, but 'chose' to do this thing.

Where I take issue is that the conception of genuinely open alternatives that forms part of the definition of libertarian free will is not satisfied by the way of thinking described above. For such 'true' options to be really choosable, it must be impossible to speak with certainty of the outcome of a choice. For if the probability of one choice is 100%, and the probability of all others is 0%, then a list of ones options that can genuinely be chosen properly includes only the first alternative mentioned. It's a different idea of genuine choice than exists in your scenario.

The difference manifests most tellingly in strong foretelling thought experiments, like that of bob. I know with certainty that bob will say pancakes, not just very high confidence, but 100% certainty. I know that it's not modally necessary that he does, and I know there is a sense in which we might say that he 'could have done otherwise' in a possible worlds style way of thinking. But when I populate the list of his genuine options in the libertarian free will sense, I require for each one to be able to say "this MIGHT happen". Even if you remove "must", replacing it with "will", the absence of "might" in the alternatives is enough to strike them from this list.

Furthermore, your account of free will does not accord with our intuitive experience of volition, in which 'maybes' and 'mights' abound, and not just from lack of data but from what we experience as decision making. Imagining the various strong foretelling scenarios which become so eminently plausible under eternalism, where we are told infallibly and in detail what we will do long before we do it, would alter our perception of volition beyond recognition. We would no longer feel we are making decisions - in fact we would feel like we were being invisibly manipulated, as bob does. That is not an argument in itself, but I argue that it is the different perspectives on the genuineness of choice options I outlined here that accounts for it.

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Posted (edited)

There are a couple of points to be made here. After the fact, the probability that the rock is pitched into the water is 100 percent. This is exactly the same if presentism were true, rather than eternalism. So how is it that presentism suddenly makes the rock-throwing a contingent affair, an affair of “might have done otherwise” and eternalism removes this possibility? There simply is no difference between the two philosophies of time, when it comes to rock throwing.

Before he throws the rock, there is no probability estimate possible, I would venture. It’s true he can either throw it or not throw it, so in that sense the scenario is 50/50, but not really, since it doesn’t take into account situations like, “I’m leaning pretty heavily toward throwing it –“ which may make the probability 75 percent, for example.

So, first, I would like you to explain how, under presentism, the probability estimates differ. If after the fact the thrown rock is 100 percent for eternalism, then so too it is for presentism.

Now, if we are discussing Norman Swartz’s scenarios in toto (and I pretty much am defending all of his arguments and not some of them), then two further points need to be stressed. The first is that, even on the assumption of eternalism, no iron-clad correct predictions of human behavior are possible; Swartz even links to what he characterizes as an unjustly ignored and groundbreaking philosophical paper that establishes this point. So situations like the Time Telescope are simply impossible; yet I used the time telescope as a thought experiment to establish how the modal logic permits free will even in extreme cases such as that of Bob. Of course, quantum indeterminism also rules out time telescopes.

And second, we need to get clear on compatiblism v. libertarianism. Comptatibilism is the thesis that free will can be reconciled with determinism. But please note: Swartz argues (and I defend) the thesis that there is no such thing as determinism at all. Neither causal, nor epistemic, nor logical, nor ontological, nor any kind you could imagine. Thus there is no need for compatibilism. As Swartz correctly notes, take determinism out of the picture, and the question of how it might impede free will does not even arise.

To go a little further: your idea, as I understand it, is that if eternalism is true, and all future events are “fixed,” then there can be no free will, because everything is already “laid out” as it were. In the past you have expressed the idea that presentism must prevail for free will to be maintained, because only under presentism is the future “open” in some sense. Is that still substantially your view?

My view is very different. For instance, as I’ve noted in the past, this word “fixed” is loaded with unintended meaning. Just because an event is “fixed” does not mean it was fated or determined or could have been otherwise. It merely means, neutrally, that something happens, and there is a true proposition that describes the event or act. In this sense it is “fixed” into history, but nothing in the words suggests that the event could not have been otherwise. Now under eternalism, time has no special “direction” as it were. The asymmetry of time that we experience is irrelevant to the eternalist. The eternalist takes the B theory of time and says that they are merely “earlier-than,” and “Later-than” relations among events. “Earlier” and “later” have no special meaning, outside of their relation. It’s like “east” and “west” have no special meaning outside their relation.

With this in mind, consider the following statement. “It is true today that yesterday, x threw a rock in the river.” Would you say that x, under this scenario, lacked free will? I trust you would not. Yesterday, he threw a rock in the river, so today it’s true that yesterday he did that thing. He could have done otherwise, clearly, but he didn’t; had he refrained from throwing the rock into the river, then the statement, “It is true today that yesterday, x refrained from throwing a rock in the river,” would instead be true. Do you agree?

Now with this in mind, the point is simply as follows. There is no logical difference at all between the foregoing statement, and the statement: “It is true today that tomorrow, x will throw a rock in the river.” The logic is exactly the same. If x throws a rock in the river tomorrow, then today it is true that tomorrow he will do that thing. But if he does not do that thing, then the statement “Today it is true that tomorrow x will refrain from throwing a rock in the river” becomes true instead. What x does tomorrow is up to him. But what he CANNOT do, is throw a rock in the river, and have it be true that he did not throw a rock in the river.

ETA: I want to make a further point on this probability thing. It's not the case, under eternalism, that what someone does is one hundred percent assured before the fact. What is the case, rather is that it is 100 percent assured that something or other will happen; AND, that what DOES happen, will be in conformance with a true proposition describing it. And after all, I see no difference between this state of affairs and how things unfold under presentism.

Edited by davidm

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Posted

Swartz even links to what he characterizes as an unjustly ignored and groundbreaking philosophical paper that establishes this point.

I want to see this please. Have you shown me this before?

As to your latest: I basically feel that this latest post of yours ignores the substance of my probability based argument by diverting the subject to presentism, which is not immediately relevant to my argument against swartz. Even if you have a case against probability as it relates to free will and presentism, you haven't addressed the meat of my argument as it pertains to your reconciliation of free will and eternalism.

I may address your case against probability and presentism, but I won't be diverted by that if (as now) it isn't relevant. Also you'll have to forgive the pace of my updates. I'm pretty busy these days with my biology. I might even make a post about it if I have the time; it's about metabolic hibernation and longevity. Which is interesting.

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Posted (edited)

I'm not sure I understand your objection to my objection, though I feel this is really the nub of the matter.

You want to maintain that if it's true today that tomorrow Bob will put on his hat, then it is 100 percent assured that Bob will put on his hat and thus he has no genuine option not to put on his hat. You deploy presentism to dodge this alleged problem, on the ground that the future does not exist, and there can be no true statements today about future contingents. This was substantially Aristotle's solution, that propositions about future contingents were not truth-valued in the present.

And I can only continue to point out that this solution is not needed. It does not matter that it's true today, that Bob will put on his hat tomorrow; this state of affairs no more impeaches his free will then the statement, "It is true today that YESTERDAY, Bob put on his hat." You do agree, right, that a statement about past contingents did not mean that those states of past affairs had no genuine alternative options, right? And I'm saying that the reference to the future is no different than the reference to the past.

You see, what MAKES it be true today, that tomorrow Bob will put on his hat, is Bob putting on his hat! Nothing has forceclosed Bob's genuine options, except that Bob himself ACTUALIZED one of his genuine options, and provided the truth grounds for the descriptive statement about what he does/ will do. If Bob had not put on his hat, than a different proposition would be true today: Today it is true that tomorrow, Bob will refrain from putting on his hat.

Edited by davidm

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Posted

Hi there. Sorry I've been out of it for a while, busy with my science stuff.

You still won't directly address my arguments though. You say you don't understand my objection to your objection, but I think I made it pretty clear: my counterargument has nothing to do with my position on presentism, and yet you insist on addressing that, and not the very specific arguments I have raised against your defense of eternalism-free will compatibility. I have to say I'm very close to again concluding that you don't answer my objections because you can't. I know that sounds confrontational but I mean it in the best spirit of friendly discussion.

If you want to prove me wrong, I'd ask you to look again at my post of the 31st and directly address the points therein, noting that nothing about presentism is said or implied. It's the nature of possibility that is under examination.

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Posted (edited)

I think we are, as usual, talking at cross purposes, because I have no idea what you think it is I have not addressed. Yes, if it is true today that tomorrow Bob will put on his hat, then it is guaranteed that putting on his hat it what Bob will do. So? It's just the modal fallacy all over again, Timothy, and no matter how many times you say you understand it, you constantly commit it. It is true that he will put on his hat. It it not true that he MUST put it on. If it is true today that tomorrow Bob will put on his hat, then it is Bob himself who will make that proposition true. It is Bob, by his own free act, who forecloses his other options; it his Bob who makes it 100 percent true that he puts on his hat. It is just that simple. You have invented a non-existent modal category: contingent, but could not genuinely have been otherwise. This invention has no basis in modal logic. If something could not genuinely have been otherwise, then it is ipso facto necessary. It is not necessary that Bob put on his hat tomorrow, Hence, it is contingent, and he genuinely could have done otherwise. I have said it before and will say it again, though not doubt to little effect. Your insistence that Bob not put on his hat, even though he does, is nothing more than asking for a violation of the law of noncontradiction. William Lane Craig, Norman Swartz and others have written on the blatant and persistent logical error you are making. Bob can put on his hat or not put on his hat tomorrow, What he cannot do is put on his hat if it is false that he puts on his hat, and he cannot refrain from putting on his hat if it is true that he puts on his hat. As I have in the past, I commend to your attention William Lane Craig's analysis of Newcomb's Paradox, with particular reference to his closing paragraphs in which he explicates the view of myself and Swartz with eloquent precision.

Edited by davidm

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Posted (edited)

I quote from the conclusion to William Lane Craig's analysis of Newcomb's Paradox.

Newcomb's Paradox and Freedom

But does that mean that in the actual world I am not free to choose otherwise, as Ahern alleges? Are we left with the theological fatalism which prompted our inquiry? By now the answer should be clear. It is I by my freely chosen actions who supply the truth conditions for the future contingent propositions known by God. The semantic relation between a true proposition and the corresponding state of affairs is not only non-causal, but asymmetric, The proposition depends for its truth on which state of affairs obtains, not vice versa. Were I to choose otherwise than I shall, different propositions would have been true than are, and God's knowledge would have been different than it is. Given that God foreknows what I shall choose, it only follows that I shall not choose otherwise, not that I could not. The fact that I cannot actualize worlds in which God's prediction errs is no infringement on my freedom, since all this means is that I am not free to actualize worlds in which I both perform some action a and do not perform a.

The above is precisely what Norman Swartz and I have been arguing, and which you have been resisting. Craig's discussion is in the context of divine foreknowledge: God knowing infallibly what you will do. The issue of future contingents having truth values today is the same issue, with God abstracted out of the discussion. The bottom line is that if the whole future history of the world has propositions about it, with determinate truth values right now, this fact in no way impeaches free will, for the reasons adduced by Craig above, and by Swartz in his many writings.

Edited by davidm

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Timothy, to simplify things as much as possible:

1. Today it is true that yesterday, Bob put on his hat. Given this true proposition, did Bob lack free will?

2. Today it is true that tomorrow, Bob will put on his hat. Given this true proposition, will Bob lack free will?

If Bob has free will on (1) but lacks free will on (2), explain why.

Good luck with the science stuff, btw. :)

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Timothy, to simplify things as much as possible:

1. Today it is true that yesterday, Bob put on his hat. Given this true proposition, did Bob lack free will?

2. Today it is true that tomorrow, Bob will put on his hat. Given this true proposition, will Bob lack free will?

If Bob has free will on (1) but lacks free will on (2), explain why.

The problem with this is a lack of information. Since most of your argumentation centers on the truth value of propositions describing actions, it's natural that you think the two options you list demonstrate the sufficiency of your case. However, I'm dealing with something else: the nature of possibility. I am arguing that certainty destroys free will, because to say something is certain is to say in a very real sense that there is no possibility of it's being otherwise. It DOES NOT mean that there is no possible world in which it is otherwise, and propositions describing it are therefore contingent rather than necessary, but nevertheless it is true to say that to do otherwise is impossible, or else describing it as certain would be perverse.

Your argument rests on misusing the concept of possibility used in modal logic, and illicitly transferring it to the more mundane and everyday sense in which we use the word 'possible'. You say that I am 'making up' some category of modal logic that doesn't exist, but in reality all I am doing is coming down on you like a ton of bricks for misapplying these concepts. You've done it in such a way that it's insidious - you've convinced even yourself. however it is a transparent rhetorical device and I have exploded it several times.

Here is what happens:

You demonstrate easily that propositions describing actions in an eternalist universe are not necessary but contingent.

You define contingent, correctly, as 'could have been otherwise'

You then say that therefore, it was possible for the action to have been some other way, and your case is made.

It looks airtight, but I have demonstrated that this only works by moving the idea 'could have been otherwise' out of the many-worlds sense used in modal logic (it could have been different, if the world had been another way) into the more everyday sense by which we judge possibilities (this would be the genuine alternative possibilities that the definition of free will we are employing requires).

Keith is my example of how your false equivalence between those senses of possible have steered you wrong. Keiths 'action' (staying in his cell) is contingent, and belongs on a list of 'possible' actions that include going for a nice stroll, or taking a rocketship to mars. However, that he will in fact stay in cell is certain, and he has no options genuinely available to him except to stay in his cell. THAT list contains only one 'possibility'. In that past you have chosen to focus on other, irrelevant aspects of the scenario, but the point that it makes should have been exceptionally clear: There are two kinds of possible that need analysing, and they are very different. There are two lists of 'things keith might do', one with many options, and one with one.

The sense of possibility, of genuine alternatives, that must be used for free will analysis, is the former, not the latter sense. When this is seen, when you see that despite using the same words, the two analyses are talking about completely different things, the accusation that a modal fallacy is committed vanished. There is no modal fallacy, because words like 'possible' and 'alternative' used to make the case for incompatibility between free will and eternalism are being used in completely different ways from the ways they are used in modal logic.

So to directly answer your challenge:

We can say that in 2, Bob lacks free will because his action is certain (or else there could be no true proposition about it). When we generate the list of genuine options, there is one thing on it. This is certainty in the gamblers sense: it is a sure bet that bob will put on his hat. In the sense used in modal logic, sure, there are lots of ways the event might have been, all of which require the world to be different, but that's okay because that's how a list of possible-worlds alternatives is assembled: bob might not put on his hat, in the world where that was always the true proposition about the event. Bob might fly to mars on a rocketship, in the world where that technology is around and in which bob likes staring at dead brown rocks. This list is populated with many 'alternative options', but it's the wrong list, so we throw it away.

In 1, as I said, there is not enough information to make a free will analysis. Of course, the fact of every action, no matter the cosmology, is certain after it actually happens. Assuming we can't change the past of course. Was it equally certain before he did it, as afterwards? We can't tell from the information given. In eternalism of course it is equally certain, before it happens, while it happens, after it happens, are all equal. In that case Bob would lack free will for the same reason as for 2 above.

We can see from this that it is not the existence of a true proposition describing an event that makes it certain. I think this might have been what you were trying to show me? That's been a point of discussion between us before, but as always I maintain that there is no determinism proceeding directly from the existence of true propositions, rather that indeterminacy precludes them. Regardless, I'd rather focus us on my counterargument about the different senses of certainty/possibility, since that defeats your argument wholesale.

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Posted (edited)

I've said before, and I will say again, that your Keith scenario simply cuts no ice. It is disanalogus to the case of Bob putting on his hat. Keith is constrained because someone stuck him in jail. What jail is Bob in, and who put him there? If Bob is in some kind of metaphysical jail because he put on his hat, then Bob is his own jailer. He CHOSE to put on his hat; the Keith scenario would be analogous to Bob if Keith CHOSE to put himself in jail.

You have given no reason to suppose that the proposition, "today it is true that tomorrow, Bob will put on his hat" constrains Bob's free will, while at the same time the proposition "today it is true that yesterday, Bob did put on his hat" somehow does not constrain his free will. The two propositions are analogous in every way. Please read again the quoted passage reproduced above from William Lane Craig. He is saying that if God knew an enternity ago that I would do x, this in no way constrains my free will. For if i do not-x instead, than God would have known THAT fact an eternity ago. I can do x or not-x, I just can't escape DETECTION of my choice.

If we abstract God out of the picture, we are simply left with future contingents that have timeless truth values. It was true an eternity ago that I would put on my hat today; so what? Had I not put on my hat today, then THAT fact would have been true an eternity ago. Again, your discussion of possibilities in this context is irrelevant. If it is 100 percent certain today that tomorrow I will put on my hat, what you omit to mention is what MADE it 100 percvent certain. Answer: I did! I actualized the 100 percent certainty by putting on my hat! I could have done otherwise, in which case it would have been 100 percent certain that I would NOT put on my hat.

You keep doing, over and over again, what Craig identified in the quoted passage, as follows"

The fact that I cannot actualize worlds in which God's prediction errs is no infringement on my freedom, since all this means is that I am not free to actualize worlds in which I both perform some action a and do not perform a.

Replace with:

The fact that I cannot actualize worlds in which a true statement about a future contingent is false is no infringement on my freedom, since all this means is that I am not free to actualize worlds in which I both perform some action a and do not perform a.

What you keep asking for, without realizing it, is not free will, which is already there, but the power to make a true statement false. True statements cannot be false by definition. You can put on your hat or not put on your hat. What you cannot have is a state of affairs in which it is true you will put on your hat but don't; or a state of affairs in which it is false you will put on your hat but do. I don't know how I can make this clearer.

Edited by davidm

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Timothy, your position seems to be similar to one that the Blighter (then posting as The Beast) expressed on this issue. As he put it, if it is true today that tomorrow Bob will put on his hat, then this means that Bob's other options, while technically possible, are modally inaccessible to him. This seems to capture your sense of "technically modally possible, without options genuinely available."

Modal logic employs a heuristic of possible worlds. A possible world simply means a logically possible state of affairs. More, a possible world just means that something is possible. If it turns out that some proposition is true at all possible worlds, then the proposition is a necessary truth. For example, there is no possible world at which triangles have four sides. So at all possible worlds, triangles have three sides.

Just because a world is logically possible does not, of course, mean that it is physically possible. Logically possible worlds include worlds at which donkeys talk and pigs fly. These are held to be possible states of affairs because they do not instantiate a logical contradiction. It's irrelevant that there are not, and cannot physically be, talking donkeys and flying pigs at our world. A world is held to be possible, if and only if it does not instantiate a logical contradiction. Unlike necessarily true statement, statements like "there are talking donkeys" are true at some possible worlds and untrue at others (like at our actual world).

Descending further, we find that there is the actual world. The actual world presupposes that it is a possible world. From this, by logical inference we conclude that there are -- a great many, in point of fact -- possible but non-actual worlds. A possible but non-actual world is one containing talking donkeys. In a more mundane sense, if Bob puts on his hat at x, then there is a possible but non-actual world in which Bob refrained from putting on his hat. Unlike the case with the talking donkeys, we understand that it was not just logically possible, but physically possible for Bob to refrain from putting on his hat, but he chose to put it on.

Now what do we make of all this? Where lies this category adduced by The Blighter, called "technically possible but not modally accessible," and your contention that there are "worlds in which there are contingent propositions but in actual fact no genuine options."?

Neither, as formulated, have any place in modal logic -- and yes, modal logic deals with the ordinary, every day sense of possibility. If it did not, what would be the use of it?

Where your formulation, and that of the Blighter, properly belongs, is in the category of "possible, non-actual worlds." Returning to Bob, if he puts on his hat, then he has relegated the possible world "Bob does not put on his hat" to the modal realm of "possible but non-actual."

Bob himself, by his own free choice, made the world called "Bob does not put on his hat" possible but non-actual. This is obvious. We render certain possible worlds non-actual every moment of every day, every time we choose.

Now, consider the proposition, "Today it is true that tomorrow, Bob will put on his hat." Put more technically, we could say: "Today it is true that tomorrow, Bob will actualize the world 'put on hat' and consign the world 'not put on hat' to the category of possible but non-actual"

Put this way, how does Bob lack free will? Because it's already true today what he will do tomorrow? Why does that matter? It's ONLY true today, because Bob WILL put on his hat tomorrow. If Bob tomorrow refrains from putting on his hat, then it is already a true proposition today that tomorrow, Bob will not put on his hat. Throughout this discussion, you commit the modal fallacy, no matter how many times you protest that you do not. From the proposition, "Today it is true that tomorrow Bob will put on his hat," you fallaciously infer that tomorrow, Bob MUST put on his hat. You say you are not doing that, but your explanation of WHY you are not doing it depends on the invention of a wholly non-existent, superfluous and in fact self-contradictory modal category, "contingent but could not have genuinely been otherwise."

It just isn't true that Bob MUST put on his hat tomorrow, and it's also not true that he lacks genuine options. What IS true is that sure enough, if it's true today that tomorrow Bob will put on his hat, he WILL put it on; but he will do so PRECISELY BECAUSE he will exercise a genuine option among two: put on, or not put on. He will put on the hat, but he doesn't have to. Were he NOT to put on the hat, he would supply different truth conditions; and so at an earlier time a DIFFERENT proposition would have been true: that today it is true that tomorrow, Bob will NOT put on his hat (see the Craig quote).

After all, Bob has to do something or other, right? What IS necessary is that Bob CHOOSE; and his choices are mutually exclusive and jointly exhaustive: He MUST either put on his hat or not put it on; he cannot both put it on and not put it on at the same time, and he cannot do neither, on pain of logical contradiction.

And what I am saying to you is to look at this obvious truth: When he picks what to do, among genuine options, there must necessarily be a true statement that describes what he does.

There is no such category as "contingent, but without genuine options," and no such category as "possible, but modally inaccessible." Both formulations are self-contradictory. If there are no genuine options, then a proposition is NECESSARY by definition; and as to modal inaccessibility, this is just a misnomer for "possible but non-actual worlds." And by our free choices we produce whole legions of possible but non-actual worlds all the time.

There IS a state of affairs, here -- two of them, actually -- that are modally inaccessible, to borrow again Blighter's term. But rightly understood, "modal inaccessibility" plainly means "necessarily false." A necessarily false proposition is one that cannot describe any possible world, just as a necessarily true proposition obtains at all possible worlds. Here are the possible worlds for Bob:

1. Bob puts on his hat

2. Bob does not put on his hat.

3. Bob puts on his hat, and it's true that he puts on his hat,

4. Bob does not put on his hat, and it's true he does not put on his hat.

What are the modally inaccessible (i.e., necessarily false) worlds? Here they are:

5. Bob puts on his hat, and it's false that he puts on his hat.

6. Bob does not put on his hat, and it's true that he puts on his hat.

5. and 6. cannot obtain at any possible worlds, because they instantiate logical contradictions, as discussed at the start of this spiel. What is modally inaccessible is simply that which brings about a logical contradiction. It is no logical contradiction for Bob to put on his hat, or not put it on. What is contradictory is for a true statement about what Bob does to also be false.

Just because there is a true statement about what Bob will do in advance of him doing it is irrelevant. Bob himself makes the statement be true at ALL times, by his act. Propositions, and the acts that they describe, are different. Acts happen AT A TIME; whereas the propositions that describe these acts, being abstract entities, exist at ALL TIMES. It is true, always was true, and always will be true, that Oswald killed JFK on Nov. 22, 1963. It was a true statement long before he did it, but his free act supplied the timeless truth conditions of the statement. Had he not done it, then 10,000 years before Nov. 22, 1963; nay, an eternity of time before that day, the statement "Oswald did not kill JFK" would have been true instead. What's true is true and what's false is false. That's all.

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Posted (edited)

I think we may even be making progress here. I appreciate that you are now dealing explicitly with possibility more or less as I have framed the issue.

Now, you have claimed that my 'invented' category, which does indeed look to be similar to blighters, is synonymous with 'possible but non actual'. It isn't, and by claiming it is exposes the vulnerability of your argument in the following way.

You may roll your eyes but I will return us to Keith. For both Keith and Bob we want to generate a list of options, and to see more than one thing on it. When looking at Bob, we want to see 'puts on his hat' and 'doesn't put on his hat on the list, so that we can say that bob has free will. HOWEVER, when we look at Keith we want to generate a list USING THE SAME METRIC, and find only one thing on it: to stay in his cell, since it's clear that Keith does NOT have free will.

My contention is that there is no such metric, conscientiously applied, that will generate those lists in an eternalist universe.

With my 'invented' category of possible but not realisable now merged, by you, into 'possible but non actual', this becomes especially hard. To generate Bobs list, we are including possible but non actual things, clearly. However, how do we now generate Keiths list? Where is Keiths option of going for a stroll? It's very clearly on the list of things which are possible but not actual. It's certainly not on the list of necessarily false things. So Keiths list is as full of so-called genuine options as Bobs list is. Problematic! There's certainly no category of possible but not actual but also physically excluded, yet that would now seem to be needed for you to be able to limit Keiths list of options to one.

You listed Bobs possible-world options perfectly well. However, what does a similar list look like for Keith?

1. Keith stays in his cell

2. Keith does not stay in his cell.

Not so? How do you keep number 2 off this list? Should it leave the list because it's impossible in the actual world? Perhaps all possible but non-actual options should leave the list, oh but we can't have that or Bob's options go too. I think we have to conclude that Keith has free will because it's possible that he goes for a stroll. Will you tell him or shall I?

What's happening is your false equivocation between many-worlds possible and 'regular' possible is falsely generating options for these lists. There IS a very basic difference between these senses of possible and denying that is going to look increasingly silly. for example, it is impossible for me to fly to the moon tomorrow: not only do I have no training or money, but the shuttle flights have been discontinued. Impossible. However, it is entirely possible in the many worlds sense that this does happen, because there is a possible world where I have more than three dollars and forty seven cents in my bank account because I am a famous astronaut and the space program of the glorious Australian empire is second to none. You are combining these senses of possibility into one, which is as silly as it looks.

Edited by Timothy

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Posted (edited)

Well, no, I will have to reiterate, first, that there is no difference whatsoever between "regular possible" and "many worlds" possible; this is plainly the case as "many worlds possible" is the formal logical explication of "regular possible." Since we have been mentioning Norman Swartz, you might want to download, free, his long out of print book on Many Worlds and modal logic. He has made it available again at his Web site.

You seem to think, for some reason, that the difference is that "many worlds" include worlds that are possible but, in actuality, not modally accessible, whereas in the "real" world, all options are genuinely open. And you apparently think so even after I have explained why this is not so, in my prior posts. This insistence of your is just as false as can be. If it were true, modal logic would be useless. What is the case, that you omit to mention, is that certain worlds are rendered "possible but non-actual" by us, by our free acts. And that is exactly what Bob did with his hat.

Also, when we are talking about possible worlds, please recall that a possible world is a logically possible world; so yes, certainly, "Keith leaves his cell" is a possible world for Keith. A world is logically possible just so long as it does not generate a logical contradiction. Remember, flying pig worlds and talking donkey worlds are possible worlds. Of course, we don't see flying pigs and talking donkeys; so they belong to the realm of possible but non-actual worlds.

So it is logically possible that Keith leaves his cell. Will he? Probably not, unless his captors free him, or he has some special Houdini-like skill at escape. Which only means as follows: when the time comes for Keith to "decide" whether to remain in his cell or leave for Hawaii, it looks as if Keith will fail to go to Hawaii, and this failure will relegate "Keith goes to Hawaii" to the realm of possible but non-actual worlds.

Which nows raises the question: so what?

For you have never grasped that your analogy between Bob and Keith is wholly fallacious.

BTW, it should be noted that even Keith DOES have free will; it's just that in this case, it's overwhelmingly likely that his free attempt to go to Hawaii will be balked by circumstances beyond his control. But that is OK. As I pointed out a long time ago, failure does not impeach freedom. We freely try, and lamentably fail, all the time to do certain things.

But, again, it's irrelevant. Keith is disanalagous to Bob.

Again, your new category of "possible but non-actual but also physically excluded" is a wholly superfluous modal category. All that is needed is "possible but non-actual." Talking donkeys and flying pigs fit nicely in that category. If we wanted to explain further and say WHY talking donkeys and flying pigs are non-actual, we could say that they did not evolve on earth. If we want to say WHY Keith will not leave his prison, we can explain that he is confined behind thick walls. So the REASONS why Keith going to Hawaii and talking donkeys and flying pigs being possible but non-actual are different, but the logic is identical: they belong to the modal category "possible but non-actual."

For the life of me, I cannot understand why you keep identifying Bob with Keith. This is the whole heart of the matter. In fact, nowhere in your latest post do you address anything in my last two posts, at least not anything of substance. Nor do you address my earlier point: What in the world is making Bob put on his hat? We KNOW what is making Keith unable to fly to Hawaii: he happens to be in prison. What prison is Bob in? Indeed, this entirely fallacious analogy begs the question: You simply assume Bob is unfree without giving us any reason whatsoever why we should think so; the Keith analogy is not a reason because the analogy is wrong.

As I said earlier: If Bob is in some kind of metaphysical prison analogous to Keith's actual, physical prison, then Bob is his own jailer. You did not address this the first time I made this point: It was Bob himself who, by his free act, relegated "Bob refrains from putting on his hat" to the category of "possible, but non-actual worlds." If you deny this, if you deny that Bob himself makes "Bob refrains from putting on his hat" a possible but non-actual world, then, please, explain why. No matter how much you may suppose you have done so, you have NEVER established the alleged connection between Keith and Bob, except in a question-begging way: assuming Bob has no free will, and then generating Keith as a colorful example of why he does not. And so we are right back to the old question: Why does Bob not have free will? Just tell me that; forget about Keith. Why does Bob not have free will?

Edited by davidm

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Let me make a follow up here: Let's look at "Keith going to Hawaii," "talking donkeys," and "Bob refraining from putting on his hat." All of them, in the scenarios we are discussing, belong to the category "possible but non-actual." For a logician, nothing more needs to be known. But, pursuant to what i wrote earlier, while all the propositions share the same modal status of "possible but non-actual," we may wish to inquire WHY they are non-actual. And now it turns out that the reasons are different for all three.

Keith going to Hawaii is non-actual because he is in prison.

Talking donkeys are non-actual because such critters never evolved.

Bob refraining from putting on his hat is non-actual because Bob himself freely made that world non-actual by putting on his hat.

Big difference, Bob's state of affairs, from that of Keith and talking donkeys!

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Posted (edited)

Something else you did not address, Timothy: although you approved of my possible worlds list for Bob, you seemed to have overlooked that the list proves that Bob has free will! So if you like the list, I guess you now agree with me.

What you did not address, with respect to that list, is that there ARE "modally inaccessible" worlds for Bob; two of them, in fact, just not the one that you think is modally inaccessible: "Bob not putting on his hat."

And, again, we must remember that "modally inaccessible" is just a misleading term. The proper term for such a modal status is: necessarily false.

So what is necessarily false for Bob?

It is necessarily false that if he puts on his hat, there will then be a true statement, "Bob does not put on his hat."

And it is necessarily false that if he refrains from putting on his hat, there will be a true statement, "Bob puts on his hat."

Edited by davidm

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I need to make a correction here. I used the term "many worlds" when i just meant "possible worlds," and we should not confuse the two, as I think Timothy is. "Many worlds" is a concept having to do, in quantum mechanics and other venues, about parallel universes that are different from our own and also inaccessible to our own. Possible worlds, the terminology I should have used, is just a heuristic meaning that certain states of affairs are possible in OUR world even if they do not occur in our world.

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wish I could join in on this conversation, that would require doing a lot of reading though.

Unless either of you wouldn't mind summarising "where you're at" at this point?

On the other hand, I could of course, and probably will, simply move my lazy ass and read all of this thread...

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