You don't have to accept that any stance on free will versus determinism has any particular implication re moral responsibility. — Terrapin Station

The relevance comes from the Kantian 'ought implies can' formula according to which you can't hold responsible someone for having done something that she could not possibly not have done (i.e. didn't have the power to refrain from doing, or didn't have an opportunity to so refrain). But it is true that this requirement can be satisfied by both (some) compatibilist or incompatibilist accounts of free will. Some philosophers (e.g. Alfred Mele or John Martin Fischer) are semi-compatibilists; they hold moral responsibility to be compatible with determinism although it isn't precluded by the lack of abilities to do otherwise. They would thus deny the validity of the 'ought implies can' formula. (So called 'Frankfurt cases', popularized by Harry Frankfurt, constitute alleged counter-examples to the formula.)

Myself, I think the mere self-conscious ability to reflect on one's own rational responsibility for the authorship of one's own past, present and foreseen actions, choices and intentions is the source of the 'ought implies can' formula (and the PAP principle); and the application of this formula to specifically moral considerations just is a dramatic but special application of this rather profound metaphysical fact about rational agency. (I also hold morality to be an integral part of rationality rather than its being extraneous as a mere source of extra-rational conative attitudes, but that is a separate matter).

Of course, one big reason for this is that there are no facts re moral responsibiilty.

It's possible that you are an agency incompatibilist, like Helen Steward. You would thus hold the core issue regarding the problem of free will and determinism to be an issue for animal agency in general. But even agency incompatibilists usually recognize that free will is best construed as a special form of agency that only rational creatures enjoy and that makes then responsible for their actions in a way animals who can't help but behave in accordance with their own natures (however non-deterministically) aren't.

Nozick would disagree: — Michael

Yes, the problem for libertarian free will that Nozick raises is this passage is the luck objection. I had mentioned this objection as well as the closely related 'intelligibility problem' and the issue of 'agent control' in this post.

It is somewhat unusual to cast this problem as a threat to the value of human life in the way Nozick does. Terrapin Station's dismissal of it on the ground that values are subjective isn't really to the point.

Also, allowing agents to somehow gain indeterministic control over their actions through there existing a bias in the probabilities of the different courses of action that they can possibly follow doesn't seem to ensure that they have the ability to do otherwise that underscores personal responsibility. For, in that case, while the agent who *might* have achieved an unintended result (when she actually intended to achieve the most probable result) doesn't thereby possess an ability to do so. It's just something that could happen, just as the ability to hit bullseye may fail to be realized when a shooter misses. But if she had missed in circumstances where she was aiming at the center of the target, she wouldn't thereby have freely exercised an ability to miss.

One way out of the problem of luck for the libertarian is to posit that the indeterministic branching occurs immediately before the time of the mental "volition", or the formation of the intention. But such accounts then run into the intelligibility problem, and the problem of agent control.

There is what seems to be an excellent explanation on the Free will determinism debate here:
https://www.youtube.com/watch?v=vCGtkDzELAI

I understand the concepts much better now - much clearer. The next video on Compatibilism was also very helpful. — FreeEmotion

I just watched both videos and they are quite good. Of course, they're introductory and very condensed, so many more subtle distinctions are glossed over, and there are a few inaccuracies. (Some of the inaccurate statements are very widespread, though, even within the recently published literature.)

The doctrine of determinism is glossed as the idea that every event has a cause. But many philosophers will rightfully separate this idea (the principle of universal causation) from the different idea, more properly called determinism (or nomological determinism), that the state of the universe at one time, together with the laws of physics, jointly determine uniquely the state of the universe at any other times. Also, the Oedipus cases, as narrated in the video, seems to illustrate the idea of fatalism, or of the possibility of foreknowledge. Fatalism doesn't necessarily imply determinism, and neither does fatalism imply determinism. And finally, many philosophers have argued that the possibility of the foreknowledge of an agent's future actions (divine omniscient foreknowledge, for instance) doesn't imply fatalism or determinism either.

Another simplification was the equation between libertarianism and the belief in the possibility of agent causation. Many contemporary philosopher now endorse varieties of 'agent causation' and also are compatibilists (and determinists). And there are also proponents of agent causation who take agent causation to be incompatible with universal determinism but who nevertheless accept the idea that every event has a cause. They reject the idea that agents have the "contra-causal" power to initiate new causal chains of physical events -- as explained in the first video -- (though actions may be construed as initiations of causal chains of other sorts, which supervene on the physical but aren't identical with physical events).

Also, the discussion of 'Frankfurt cases' and of the principle of alternative possibilities (PAP) makes it sound like compatibilists all believe this principle to be incompatible with determinism, and hence believe free will not to require it. But quite a few contemporary philosophers, dubbed 'new dispositionalists' by their critics, endorse both compatibilism and PAP. They have, in other words, an account of what it means to say that an agent could have done otherwise than what she actually did, and their account is specifically designed so as to make possession of this ability (and therefore also PAP) consistent with determinism.

There'd be more to say about what appears to me to be a misconception pertaining to the way agent-control relates to responsibility and free will in Patricia Churchland's account. But her views are very widespread and they are accurately reported in the video.

Your solution is quite similar to Russell's way to deal with the analogous instance of the Liar Paradox (Russell's paradox) that arose from attempts to realize the logicist program in the foundations of set theory (and of arithmetic). He devised the theories of types in order to solve the problem. In that case, the proposed solutions seem somewhat arbitrary and artificial. But in the case of your own solution, it seems to be more to the point since it is such a natural reading of the intent of Socrates' assertion.

Again, that P is logically possible is only the case to some S at some specific time, because of what logic is--namely, a way of thinking about the world. That doesn't imply that S can't think about the world when he does so that he thinks that P(t). But that doesn't imply that at t P(t) is true. It's not. It's only true to S, at the time that S thinks it. — Terrapin Station

This is indeed exactly how I understood your position.

What it is to be logically possible or logically impossible is for some individual to think about things a particular way. There's nothing else to it.

But you are claiming something else. You are claiming that for something to be logically possible or logically impossible at time t there must not only be some individual who thinks about it, or be able to think about it (at some time or other), but, in addition to that, this individual must be thinking about it at time t.

This is strange, but, coming to think more about it, it doesn't appear to be inconsistent. I still prefer the view that operators of logical possibility, just like operators of alethic, metaphysical or nomological possibility (but unlike operators of temporal or epistemic possibility) are tenseless. The view that they have truth values only at the time when they are thought about strikes me as somewhat idealistic or solipsistic rather than pragmatic. It also introduces a strange disconnect between logic and natural laws, as if natural laws weren't also pragmatic abstractions. But, again, nothing much hinges on this. At least I have come to see that your view may be consistent. So, let us agree to disagree.

<sigh> it's not also a logical possibility at the time in question.

At the time in question, it's only a metaphysical possibility.

This is because logic only exists once there are people. That's not the case with the world in general.

This is relevant to there being an example of a metaphysical possibility that's not also a logical possibility. I'm not saying that it's relevant to anything else. — Terrapin Station

When you say that "something" is a logical possibility at time t, this can be interpreted in a specific way that is perfectly intelligible but that is clearly not how you mean it. This "something" must have the form of a predicate such that it may be true at some time and not at other times. For instance, some specific apple's being ripe would be such a predicate. This could be written R(...), where the argument place is a time variable. Then, saying that the apple's being ripe is a logical possibility at time t means that R(t) is logically possible.

But what you mean is something different. You rather mean that the saturated expression R(t), (or rather the proposition that is expresses), not the unsaturated predicate R(...), itself may be logically possible or logically impossible depending on whether or not there happens to be human beings (or other sorts of logic users) in the temporal and/or spatial vicinity of the apple. I think this is nonsensical, and it is absolutely not required by the thesis that logic is human dependent, in a pragmatic or Kantian sense. The relevant sense of human dependence does't require that the objects thought about be in the spatial or temporal vicinity of the human beings evaluating the logical possibilities of propositions about them since our cognitive reach isn't limited to the present or to the surface of the Earth, say.

But I am not going to belabor the point. We will have to agree to disagree. This excursus was rather off topic anyway.

The reviewer should ask why whether they weren't logical impossible or possible at the time matters to the author in the context of the article. Did the article have something to do with whether there was logic 100 million years ago? — Terrapin Station

Well, this is pretty much what I have been asking you in several recent posts. I have been consistent in my insistence that claims about the logical possibility of scenarios or propositions depicting the past have absolutely nothing to do with whether there was logic in the past.

In our case, you asked for an example of a metaphysical possibility that's not a logical possibility, so I gave you an example.

The metaphysical possibility that you offered was about the past state of our universe at the time when the first stars formed. It was about the "metaphysical" possibility that this state could give rise to the evolution of life. This is also a logical possibility since the possibility of live evolving from that initial state "(has nothing) to do with whether there was logic (billions of) years ago" (as you now seem to be acknowledging). The fact that there was no logic back then is no more relevant to the evaluation of the logical possibility of the claim, regarding the evolution of life, than it is relevant to the relative populations of different species of dinosaurs.

Right, logical anything, including possibility and impossibility, is always to someone, and not only that, but it's also going to be only relevant to the particular logic that person is using at that time. Logical possibility and impossibility do not obtain outside of that. Not on a coffee table, or to amoeba in the ocean, or 3 billion years ago, etc. — Terrapin Station

So, this means that on your view, Professor Station was correct and the logical criticism of the conclusion of the study by the reviewer was misguided. The editor of the journal should publish the study without any revision since the result hasn't been shown to be logically invalid. It was not logically impossible that there were more triceratops than pterosaurs, more pterosaurs than velociraptors, and also, more velociraptors than pterosaurs. Our contemporary logic just doesn't extend to the distant past.

Again, I do not agree with this. Do you understand that I do not agree with it? — Terrapin Station

Of course, this is precisely why I present arguments as to why this claim that you are disagreeing with is reasonable and why your disagreeing with it leads to absurd results. If you are not agreeing with the idea that the truth of logical propositions isn't temporally bounded, then you must be agreeing with the defense provided by the author of the paleontological study. You must also be agreeing with the claim that scenarios that are logically impossible on Earth, those very same scenarios, are not logically impossible on Mars. If fact, they are not even logically impossible on the coffee table between us (assuming we would have had a conversation over coffee) since there is no logic literally 'on' the coffee table.

Why are you having a problem answering whether during the first star formation, there was logical possibility?

If there's no logic, is there logical possibility? — Terrapin Station

If there is no logic, there is no logical possibility, but there is logic: our logic. And the truth of modal logical claims is not temporally limited anymore than it is spatially bounded.

Imagine that a team of paleontologists comes up with the following discovery about the past: At some point during the Cretaceous, over a period stretching more than one million years, the average population of triceratops was exceeding the average population of pterosaurs, which themselves were more populous than the velociraptors, which themselves were more populous than the pterosaurs.

They thus submit their putative discovery to a scientific journal and one reviewer sends an e-mail to the main author of the study pointing out that their main result has the form of a conjunction of propositions making up an inconsistent triad. That's just not logically possible. The main author replies that it may very well be that this would be logically impossible now, but none of the three reported disjuncts are nomologically impossible, and it is irrelevant that their logical conjunction isn't logically possible now since it happened over 100 million years in the past, at a time when there was no logic.

Upon receiving this reply, the reviewer scratches her head and ponders over what to respond to Professor Station.

I'm not talking about our perspective. — Terrapin Station

No but you are talking from our perspective. When we make claims of logical possibility regarding contemplated scenarios unfolding here or elsewhere, now or in the past or in the future, we are envisioning those logical possibilities from our own perspective.

I'm talking about during the first star formation. It was a metaphysical possibility that life would evolve. It wasn't a logical possibility. So that's an example of there being a metaphysical possibility and that's not a logical possibility.

You are again conflating two different claims. First, there is the claim that at the time of the first star formations there wasn't yet a practice of logical evaluation of consistency of propositions, validity of inferences, etc. (just as there was no musical or scientific practice, say). And then there is the claim that it was not a logical possibility that something occurred at that time. The first claim doesn't entail the second because logical possibilities don't have temporal boundaries anymore than they have spatial boundaries. If it's logically possible that there are more than two rocks on Earth, then it's also possible that there are more than two rocks on the surface of Mars regardless of the fact that there is "no logic on Mars" in the sense of there not being such a socially instituted practice over there.

The task wasn't to give a "context-independent" example, and if that had been the task, I'd say that there is no such thing.

So, the implied interpretative context, in all claims of logical possibility, is our own practice of logical evaluation of propositions and inferences. There doesn't exist this context-free 'view from nowhere' perspective relative to which a determinate scenario is nomologically possible but is neither logically possible nor logically impossible.

Great. So an example of there being a metaphysical possibility that's not a logical possibility is that during the first star formation, it was a metaphysical possibility that life would evolve, but it wasn't a logical possibility. — Terrapin Station

No. The contemplated scenario about the eventuality of life evolving from those initial conditions is both a nomological possibility and a logical possibility. The fact that there was nobody using logic doesn't make the scenario logically impossible from our perspective. Likewise for the scenario about there being an unknown uninhabited planet permanently hidden on the other side of the Sun. There being such a planet over there doesn't fail to be a logical possibility just because, according to you "there is no logic over there".

When I acknowledge that if there is no logic then there is no logical possibility, I of course meant, not logic anywhere at anytime. But it's not true that there is no logic. There still is our logic, and it's the only logic that counts for the evaluation of our claims of logical possibility.

Why are you having a problem answering whether during the first star formation, there was logical possibility?

If there's no logic, is there logical possibility? — Terrapin Station

If there is no logic then there is no logical possibility. But it is irrelevant to our claims of logical possibility regarding the past state of the world whether of not there "was logic" in the past. Our claims of logical possibility are our own. They are pegged to our interpretation.

Likewise, our claims about the logical possibility about distant places in space aren't pegged to "the logic" at those places.

If we ponder over whether it is logically possible that there are non-rational Martians on Mars and that the tallest Martian is taller than the shortest Martian, then it doesn't make sense to say: it's not logically possible on mars, because martians don't use logic. The reason why it's not logically possible is our logic, not anyone else's.

Right. So during those events, was it logically possible for life to evolve? — Terrapin Station

Why is your statement of logical possibility tensed? It makes sense to tense the proposition that the modal operator is operating on since this specifies the time frame of the events you are talking about. But why tense the modal operator also? If you mean to peg the interpretation of the concept of logical possibility to the understanding of whatever people might have been alive at that time (if any), then your question would be more conspicuously phrased something like:

"During those events, was it logically possible for life to evolve from the standpoint of the people who were living at the time, if any?"

The answer would be 'no' since there weren't any living people. But this is not what we mean when we say, for instance, that it is logically possible that, at that time, conditions weren't such as to prevent the future evolution of life. (And if conditions were such as to prevent the evolution of life, anyway, then the impossibility would likely be nomological rather then logical, or so it seems to me.)

So during those events--the first star formation, say, was there logic? — Terrapin Station

There was no logic, no music and no literature. But this has no bearing at all on the question, for instance, whether or not it is logically possible that there were roughly as many spiral galaxies as there were elliptical gallaxies. That's indeed logically possible, arguably. It is not, however, logically possible that there were more binary star systems than there were stars. In those statements, "there were" is past tense, but "it is" is intemporal. It is not pegged to a specific time but rather to our own interpretation of logical possibility.

Right, so do you think it's meaningful to say that the first stars were forming at "some specified time frame" in the past? — Terrapin Station

Yes. That's meaningful. But episodes of star formation are events. They are not points in time, and neither are they "specified time frames" existing on their own some time shortly after the big-bang.

Why would that be meaningful but it's not meaningful to say that things occurred 15 (or 18 or whatever age you accept) billion years ago? — Terrapin Station

But I quite agree that it's perfectly meaningful to say that things occurred billions of years in the past (I am just agnostic regarding the exact moment of the big-bang). But it is one thing to say that there were things happening over some specified time frame in the distant past, and it is another thing to say that there was a "point in time" at some specified moment in the past. It's the latter that I can't make sense of.

In fact, I had been insisting that it is meaningful to say that there are distant past events that possibly occurred, as a matter of logical possibility, while *you* were denying it on the ground that there were no human being back then and hence that there was "no logic".

Would you say that there was a yesterday, and that it was before today, but after last week? — Terrapin Station

For sure. But that is just to say that it is meaningful to say that things occurred yesterday, and that they thereby occurred earlier than today and later than last week.

Right, so you'd also say that you can't answer meaningfully whether there was a time/a "point" in time (in quotation marks for a reason) that you had lunch or whatever meal you might have eaten yesterday? — Terrapin Station

That's correct. Because moments in time when specific sorts of events are truly said to have occurred are coarse-grained in a way that must be consistent with the typical duration of those events. For this reason, I happen to think that the idea of 'the present' as an unextended temporal location that separates the past from the future is unintelligible. For any meaningful use of the concept of the present, it has some sort of temporal 'thickness'.

Right, so do you think that there was a time when the big bang occurred? — Terrapin Station

This question can't be answered meaningfully unless it is being interpreted within the conceptual framework of some fundamental physical theory. It's likely that in relation of such a framework, the question is formulated badly. The idea of a continuous linear ordering of moments in time, or of an initial moment, may break down.

I didn't write "or say at the moment of the big bang"? — Terrapin Station

Yes, OK, you said that also. That's not very helpful. Should we now be talking about space-time point singularities in the context of general relativity and quantum cosmology? You haven't explained how your question about there being, or there not being, a "point in time" at some specified moment in time, whichever it is, makes any sense.

Didn't I say "at the moment of the big bang" a couple times? — Terrapin Station

Not quite. You mentioned a moment shortly after the big bang. But then you are asking me if there was a "point in time" at that time. This is just like asking if there is a point in space in the corner of the room. But you've just mentioned such a point. How could there not be a specific temporal location "at the time" you just specified as a specific temporal location?

So you don't know if there was a "point" in time billions of years ago? Do you know if there was a point in time yesterday? — Terrapin Station

What does a "point" in time look like? This sounds like the propositional reification of an unsaturated predicate. I can tell you if there was a point in time when the sun was shining. Temporal point are rather like spatial locations. You can tell if there is something or other at this or that place or if there is (was, or will be) something occurring at this or that time. But mentioning a time and asking if there is a point in time at that time seems strangely confused. It's like asking "is there a 'point in space' in the corner of this room?".

Do you think it makes sense that there was a time billions of years ago, just after the big bang, say? — Terrapin Station

I am not sure exactly how to evaluate the proposition "there was a time billions of years ago". What would it mean for its being the case that there isn't "a time" at some point in the past?

At that time, not now where you're thinking about that time, is it logically possible for intelligent beings to evolve or not evolve? Yes or no. I'm not going to move on until you answer yes or no, despite how much you try to avoid doing so. — Terrapin Station

I've explained to you that your question conflates two different ideas. I've explicitly disambiguated those two ways to read the question. The answer, according to the first construal, is "yes". The second construal, which seems to be your intended construal, doesn't really make sense. In any case, it's not related to our ordinary understanding of logical possibility according to which it is logically possible that an atomic war could have wiped out humankind ten years ago and that the earth would have continued orbiting the sun.

Say it's 10 billion years ago or so.

Is it logically possible at that point in time for intelligent beings to evolve or not evolve? — Terrapin Station

You must resolve the ambiguity between the idea of (1) its being logically possible (according our conception of logic, now) that something could have been the case at time t, and the different idea of (2) its being logically possible at time t that something is possible at that time.

The second construal presupposes that there is something about the claim that must be indexed to the principles of logic that are being used by whoever happens to be alive, and sapient, at that time. But this is no part the the usual idea of logical possibility, where the criteria of logical consistency are our own criteria, and not the criteria of the creatures that may populate the contemplated scenario (if there are any).

It's not just imagined. Persons didn't exist at one point in the past. There was no logic. No logical possibilities. But there were metaphysical possibilities.

It's not logically possible for no intelligent beings to evolve. If no intelligent beings evolve, there is no logic. You're assuming that logic is something other than a thing that intelligent beings do. — Terrapin Station

The claim that it's not logically possible for no intelligent beings to evolve conflates two things. It conflates the idea of this scenario not being logically conceivable by us, and the idea of this scenario describing a state of affairs where our logic (or anyone's logic) has not been invented and/or made use of within the imagined situation.

Your claim doesn't make anymore sense than the claim that is it logically impossible for there to be distant planets where not life evolved, since in that case the is no logic on those planets.

I just explained this to you. Imagine that there are no people. There would still be metaphysical possibilities. There would be no logical possibilities. There would be no logic period. — Terrapin Station

This is not an example of something that is a metaphysical possibility and not a logical possibility. It's rather an imagined scenario (for instance, an alternative history where human beings didn't evolve) where nobody invented logic. But it is logically possible that no intelligent beings had evolved: for instance if a huge meteorite had hit the earth 100 million years ago and killed all the higher life forms. So the imagined scenario is logically possible. Else, you'd have to say that it's logically impossible for mankind to become extinct (unless other sorts of beings somewhere, on another planet maybe, still go on thinking logical thoughts). But logic alone doesn't rule out the possibility of mankind's extinction at some point in the future.

I'm using logic to refer to a language about relations on an abstract level, and more specifically, it has to do with implications/inferences of relations.

Not everything in the world is a language about relations, is it? — Terrapin Station

OK, fine. I would call De Morgan's law, modus ponens, modus tollens, or the axioms of first order propositional logic "laws", but if you would rather view them as "relations... (that have) to do with implication/inference relations", that is perfectly fine with me.

I am no less puzzled by your claim that logical possibilities are a subset of metaphysical possibilities.

Again, can you think of just one metaphysical possibility that isn't a logical possibility?

I wouldn't say that there are any laws of formal logic.

There are basically language games that are set up as conventions re different species of logics, where logic, as I had said, is a subjective linguistic reporting of how individuals think about relations on the most abstract level. — Terrapin Station

You are the one who brought up the topic of logical possibility and claimed, contrary to traditional wisdom, that logical possibilities are a subset of metaphysical possibilities. I am usure how this further characterization of logic explains the claim that you made. Maybe it would help if you would give an example of something that, in your view, is a metaphysical possibility even though it is not a logical possibility. That would possibly help me make sense of your strange suggestion.

In my view that explanation is just compounding problems (note that my comments below are in the context of what's functionally going on, with respect to what's coherent or not, re conventional uses if terms):

* "Possible worlds" talk doesn't make sense except as talk about what is metaphysically possible in the actual world (which for a determinist is only one thing for each "branching point" so to speak . . . also, I see logical possibility as a subset of what's metaphysically possible, although determinists would have to say that it's the subset of things that are possible to non-contradictorily imagine; that, however, is still a subset of metaphysical possibility.) — Terrapin Station

What's logically possible is whatever isn't ruled out by the laws of formal logic alone. Whatever isn't self-contradictory is thus logically possible. Metaphysical possibilities, however you construe them, seem also to exclude propositions that are false because they are ruled out by a priori conceptual truths or by the laws of nature. (But see also Kripke on the metaphysical necessity of identity or of origin). It is very strange to say that logical possibility "is a subset of what's metaphysically possible", rather than the other way around.

* I don't know if you intended them to, but alethic or temporal possibility wouldn't refer to anything other than metaphysical possibility (they'd just be limiting the consideration to metaphysical possibility re truth-value judgments or changes that obtain relative to something)

Something is an alethic possibility ('a-possibility') if there is a true subjunctive conditional (e.g. a causal conditional) in which it figures as the consequent.

e.g. I arrived at work late because I forgot to set my alarm clock but it is a-possible that I would have arrived to work in time since if I had (counterfactually) not forgotten to set it then I would have arrived to work in time.

What is the allowed range of counterfactual antecedents that make alethic possibility statements either true or false is of course a pragmatic contextual matter that a semantic model must be sensitive to. (There seems to me to be a flaw with David Lewis's 'counterpart' models and their seemingly context insensitive similarity relations between possible worlds. Saul Kripke seems to me to provide a better informal account in Naming and Necessity.)

A temporal possibility is a possibility for the future that may become actual after the time has come. When the time has come, and the proposition now represents the past, it becomes (temporally) necessarily true or necessarily false. The range of possible worlds under consideration, in this case, is the set of possible worlds that share the same past with the actual world, at a time, and are branching out in the future consistently with the laws of nature. Just in case determinism is true, of course, then there is no branching out. There only is one actual future.

My point only was that epistemic possibilities depend on neither of those two modalities since they are premised on my ignorance regarding the actual world and don't always depend either on whatever is as of yet unsettled (for the future) or on what would have happened in counterfactual circumstances.

* "Possible worlds as semantic models" -- we can note that the semantic models that individuals happen to possess (meaning is subjective and only obtains insofar as individuals actually think it) are actualized possibilities, but this is still metaphysical possibility (and rob a deterministic actualized (or to-be-actualized possibilities) are the only possibilities there are)

No. Semantic models aren't "actualized possibilities". This is nonsense. They are sets of characterizations of possible worlds with only one among them being labelled as the actual world. When something is actual, then it is possible but only one possible world is actual.

* The idea of "subjective probabilities" is just nonsense--if there are probabilities and that's not just an illusion, that's going to be a name that picks out some objective relational feature(s) of the world

If you throw a die that you know to be fair and balanced, then, regardless on the laws of nature being deterministic or indeterministic, after the die has been thrown, but before you are informed of the result, the subjective probability for each one of the six conceivable results, from your own epistemic perspective, is p = 1/6. I am unsure why you would think this is nonsense. It is just part of the normal course of practical deliberation for people to make use of their own subjective probability estimates of the consequences of various possible actions, even when the consequences already are settled conditionally to their choices.

* It's fine to note that we can be ignorant about which possibility obtains, where we believe that prior to something obtaining, there is more than one possibility, but if we're determinists we do not believe this; we believe that there is only one thing that's a possibility prior to each "branching point,' and our ignorance is about which thing was possible. Thus (a) ignorance isn't the same thing as some sense of possibility, and (b) this is not a different sense of possibility than metaphysical possibility; we're merely talking about our ignorance and beliefs re metaphysical possibility.

Those are just dogmatic assertions that you are making. Determinists and indeterminists alike usually agree about the fixity of the past. Yet, it makes sense to speak about epistemic possibilities regarding past events.

* Mathematics (and logic) are simply languages that report our subjective understanding of contingent relations, as they are thought about on the most abstract level, and

* Truth-value is a judgement about the relation of a proposition to something else (the exact something else being whatever the individual believes to be the pertinent relational consideration (for the context at hand). That could be their perception of the external world, or consistency with their stock of previously adjudged propositions, or usefulness per their judgment, etc.)

Well, yes, sure. That's exactly what epistemic modalities are about.

Again, it's not at all plausible to me that beliefs about possibility are beliefs about something other than whether an event can metaphysically obtain.

At least where one is using the term "possibility" in anything like its conventional sense. — Terrapin Station

The words "possible", "possibly" and "possibility" have a multiplicity of senses and not just one single conventional sense. Just look up the two or three main definitions in any common English dictionary, as well as the various examples of common usage that they give.

It is not at all plausible that epistemic possibilities really are beliefs about the metaphysical (or alethic, or temporal) possibility of events. One good way to get at the difference is to pay attention to the fact that most modalities can be construed as statements regarding some set of possible worlds (semantic models). But epistemic possibilities always are statements about the *actual* world. (See the examples in the Wikipedia article on epistemic possibility and the mention of the actual world at the very beginning.)

If we are waiting for the bus, and we are unsure if we may *possibly* have missed it, and ought to walk rather than wait any longer, we are not pondering over whether there might be possible worlds other than the actual world where the bus has passed ahead of schedule. We rather are pondering over whether it is at all likely (where "likely" expresses subjective probabilities) that it has passed ahead of schedule, and we thereby missed it, in the actual world. This "possibility" is entirely premised on our state of ignorance regarding some features of the actual world.

Another telling example might be this. If I endeavor and seem to have succeeded in proving a mathematical conjecture then I may still wonder if the conclusion might not be false because I have made a logical mistake while constructing the proof. So, I think it is still possible that the conclusion may be false. But the conclusion being a mathematical proposition, if it is true in this world then it is true in all possible worlds. (In other words, the truth of mathematical proposition isn't a contingent truth). Therefore my belief that, for all I know, the conclusion might still be false (because I am still unsure about the validity of my proof) doesn't entail the claim that there might be possible worlds other than the actual world where the statement is false. The possibility of its being false is purely epistemic.

What would be the grounds for a claim that a proposition like "There is a possibility that x" has a structure like "(NP(A)" (or EP(A) or EP(NP)A) or whatever)? — Terrapin Station

I am simply trying to understand *your* suggestion that it may be incoherent to interpret epistemic possibilities to be "about" anything else than nomological possibilities. I provided a simple counterexample regarding my girlfriend possibly being at home (for all I know). It would help if you would explain what you meant with your "about" claim if it's not related to content.

I'll be away from my computer over the next several hours.

It's not as if all beliefs are about possibility. — Terrapin Station

Of course not. But you were the one expressing doubt that epistemic possibilities could coherently be thought to be "about" anything else than nomological possibilities, not me. I had construed that as the claim that epistemic possibilities have the form: 'for all I know, A might be nomologically possible', or, in shorter form, 'EP(NP(A)'. If you meant something else with your suggestion that all epistemic possibilities are "about" nomological possibilities, I don't know what that is. You would need to explain what you mean by "about" if it's not propositional contents.

What in the world does that have to do with what I asked?

I didn't say anything about the only sorts of propositions that might be true. In fact, I didn't say anything about propositions or truth whatsoever.

I didn't say anything about "complex" versus "basic" propositions. — Terrapin Station

What you asked me was this: "Actually this is a better question: why wouldn't epistemic possibility be beliefs about nomological possibility? I'm not at all convinced that it's coherent to say that it's anything other than that."

Are you not familiar with the idea that the contents of beliefs are propositions?

It really sounds like you were doubting that epistemic possibilities can coherently be said to be about anything other than propositions of nomological possibility. That would make those contents complex propositions of form (NP(A), where A is a simple proposition in subject/predicate form, and the belief itself (the epistemic possibility) has the form EP(NP(A). I have no idea why you would believe that, or believe that beliefs of the form EP(A) that aren't themselves "about" nomological possibilities, are necessarily incoherent.

To put it quite simply, when I say that, for all I know, my girlfriend may still be at home, this statement of epistemic possibility is about my girlfriend being at home. It's not about any sort of nomological possibility. I may not even believe that there are laws of nature. (Maybe I am a Humean regularist about laws, and I don't believe in natural necessities at all, say).

Actually this is a better question: why wouldn't epistemic possibility be beliefs about nomological possibility? I'm not at all convinced that it's coherent to say that it's anything other than that. — Terrapin Station

I'm unsure why anyone would think that the only sort of propositions which, for all one knows, might be true, are complex propositions regarding the nomological possibilities of basic propositions. There are more things under the Sun than just nomological possibilities. Maybe a determinist would believe something like that (that everything that is true is nomologically necessary) since, on her view, everything that will ever become temporally necessary in the future always has been in the past also. But then, that would only be true if we assume the nomological necessity of the 'initial state' of the universe.

Wait, in the situation I'm presenting, what are you claiming the person believes is nomologically possible? — Terrapin Station

There isn't any proposition that she is claiming to be nomologically possible, if I understand you. Rather, she is claiming that one and only one among two propositions, A and B, is nomologically possible but she doesn't know which one it is. (If she would care to draw logical inferences from her own beliefs, though, she could conclude to the nomological possibility of the disjunctive proposition 'A xor B', as I've suggested to Michael, since this is a valid inference from (nomological) modal logic.)

Otherwise, how exactly does that amount to mixing anything up, because all I did was talk about what they do and do not believe? — Terrapin Station

That's because in the case you are describing, as I've displayed through formalizing it, there are two different sorts of modalities involved. It is a case where you avow ignorance regarding which one among two propositions is nomologically (or temporally, maybe) impossible, while the other one is nomologically possible, although you don't (yet) know which one. Since epistemic possibility doesn't entail nomological possibility, there is no validity in inferring the conclusion that you believe both to be nomologically possible. It's just your conflating the those two sorts of 'possibility' that generated the invalid inference and the false conclusion that you thereby believe both to be possible conjointly.

I had said simply said this, which you never addressed — Terrapin Station

Yes, I did address it. You didn't reply to my comment about it. Maybe you missed it.

So when you don't want to deal with some particular individual's beliefs, you just claim that that is not a rational person. — Terrapin Station

Everyone has inconsistent beliefs but there ought to be a consistent core. Who said I wan't prepared to deal with it on a personal level? We were discussing rules of inference that are valid for epistemic logic, presently. For those rules to apply to the belief systems, or epistemic perspectives, of real persons, there must be a minimal presumption of rationality. When a person believes that P, and also that Q isn't logically consistent with P, she isn't normally prepared to accept that, for all she knows, Q. If she is nevertheless prepared to accept Q as an epistemic possibility, then she must thereby either acknowledge that she doesn't really believe that P for sure, or be prepared to revise her belief that P and Q are inconsistent.

If a person shows no tendency to revise some of her beliefs when they are shown to be mutually inconsistent, then there is no saying what it is that, for all she knows, might be true, and epistemic modal logic breaks down as a means for interpreting her. (Look up Donald Davidson on 'radical interpretation', the 'constitutive ideal or rationality' and also the 'principle of charity'.)