Your hypothesis is that (i) there is a thing called the will, (ii) the will is not subject to causal laws (iii) the will causes human action. This is a substantive hypothesis, it is not an apriori truth by any way shape or form. — MetaphysicsNow

It's pretty simple. What I claim is that if your "causal laws" exclude the will as a cause of human action, then your causal laws are incorrect. So if your process of analysis which seeks to understand human activity according to your causal laws proves to be deficient, then this is evidence that my claim is correct. Therefore a procedure which changes the applied causal laws and approaches with different causal laws may be of assistance.
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The question, then, is in any given case what leads up to the will causing a given human action or prevention of human action (nb, there is also the question how the causal mechanism between will and action works, but that is a different question). — MetaphysicsNow

Why is this a relevant question? If the will is a start of physical action, and not a continuity of physical action, then what point is there in considering the physical conditions prior to the actions of the will? Further, we have already dwelled on the psychological, and determined that there is no necessary connection between the intelligible decision, and the act of the will. We ought to be stymied right here.

However, I propose we look at the realm of the unintelligible, which is related to the intelligible, as opposed to it, but still within the same category, as hot and cold are within the same category. So we are in the category of the psychological rather than the physical, but the "decisions", the cause of action are not conscious decisions at all, and therefore not intelligible. The unintelligible is characterized by an inapplicability of the laws of logic. So for example, "possibility" refers to something in which the fundamental law of excluded middle does not apply, and is therefore unintelligible. Do you see that? So as much as we try to make possibility intelligible through probabilities and modal logic, there is something about it which remains inherently unintelligible.

Now let's approach your question. Let's say that there is a relationship between will, and possibility, and this is what "leads up to the will causing a given human action". This is why we cannot go to "physical conditions", because a possibility is non-physical, and we cannot refer to conscious decisions of the intellect which utilize "causal laws" because these are laws of necessity, based in physical observations, so they do not apply.

You also seem to be implying that there is no rational account for that either. That seems to rule out any kind of research program into how the will is supposed to get in on the act. — MetaphysicsNow

Does what I have said above, qualify as a rational account? I have not ruled out "research", but directed the research in a particular way, and that is toward the nature of "possibility". Do you think that this is the right direction? The conscious intellect wants to understand the world in terms of logical necessity, and produces concepts like cause and effect. It wants to know with certainty. However, the world keeps giving the human being possibilities, and forcing the will to act, in a way which the intellect cannot keep up with. Actions are required very rapidly as time passes, and the intellect is not capable of keeping up to, and making a decision for every act which is required. So the will may act in a way which is unintelligible to us. This is made necessary by the existence of so many millions or billions of miniscule possibilities which the conscious mind cannot even fathom.

(nb, there is also the question how the causal mechanism between will and action works, but that is a different question). — MetaphysicsNow

This is an interesting question, because it approaches the question of what type of thing the will is, and this goes to the heart of the mystery of life, what is the soul. But as you say, it is a different question, and I don't think we even have a way to approach it without an understanding possibility. In Aristotle's biology the forms of life are described according to their capacities, and the capacities are described as potencies which are based in possibilities, potential. This is a different perspective from modern biology which tends to proceed through physical descriptions. I think there is a need to unite these two perspectives, i.e., such and such physical description corresponds with such and such capacity, which corresponds with such and such possibilities.

To my mind, the concept of self-control is partially distinct from the concept of motivation.

Motivation is a relationship of attraction between a person's biological drives such as sex, hunger, companionship e.t.c, and the person's environment that triggers or suppresses the person's drives and that as a consequence compels or inhibits the person's behaviour in pursuit of satisfaction.

To my mind there is no such thing as "self-motivation". What we call self-motivation is more accurately described as being in a state of psychological momentum towards a goal-state when one's drives are already awoken. The likelihood and extent to which an individual achieves his goal-state is a function of "self-control", which refers to the extent to which the individual can ignore competing reward signals that threaten to divert his actions towards less rewarding behaviour.

To my mind "self-control" should really be called "partial-self control", since it not only consists of an individual's partially learned neurological abilities and habits, but also the degree of social support the individual receives as well as the quality of environmental feedback he receives. Together they keep the individual's productive behaviour on track, by determining the extent to which the individual continues to anticipate future rewards as a consequence of his actions, and the extent to which the individual finds working towards the goal satisfying in and of itself, before the goal state is reached.

Why is this a relevant question? If the will is a start of physical action, and not a continuity of physical action, then what point is there in considering the physical conditions prior to the actions of the will?

It's not about considering physical conditions, perhaps the conditions are not physical. The point is that at some time t, the will intiates something (or prevents something from initiating), but - if you are right - the will need not have done. The question then is why it did behave in that way rather than not behave in that way. Why is that question relevant? It is relevant because answering that question is the only way we will discover more about what this thing called "will" you are talking about actually is.

So for example, "possibility" refers to something in which the fundamental law of excluded middle does not apply, and is therefore unintelligible. Do you see that?

No I do not see that, because it is a contentious position you cannot just help yourself to. Maybe you are right that we need a metaphysics of modality, but most people who have worked on the metaphysics of modality believe that possibility is constrained by the laws of classical logic - including the law of excluded middle, but more specifically the law of non-contradiction. Perhaps we can do without the law of excluded middle (intuitionist logics for instance) but the law of non-contradiction is a great deal more difficult to do without and provided that the law of non-contradiction holds, possibilities are always going to be intelligible.

A realist who interprets the concept of Necessity as being a mind-independent principle of nature that is charted by causality, will have to either deny humans of will, or reduce the human will to causality rending the notion of free-will as meaningless.

An anti-realist who identifies the concept of necessity not as a description of nature "in itself" but with what we think ought to happen or what we intend will happen, will generally be a "free will compatiblist" with respect to causality, since he will view causality as purely a language for describing past orderings of events.

It should be clear that for both the realist and the anti-realist, knowing more physical facts cannot force either to change their position.

and provided that the law of non-contradiction holds, possibilities are always going to be intelligible. — MetaphysicsNow

No, that's the problem, the exact opposite is the case. So long as we allow that possibilities are real things, there will always be something inherently unintelligible about them. Do you recognize that you cannot comprehend a possibility by referring to the logical categories of what is and what is not? How would you class possibility, neither is nor is not, or both is and is not?

No I do not see that, because it is a contentious position you cannot just help yourself to. — MetaphysicsNow

How is this a contentious issue? Clearly the real existence of possibility violates at least the law of excluded middle, if not the law of non-contradiction and the law of identity itself. Where is the contention?

Perhaps we can do without the law of excluded middle (intuitionist logics for instance) but the law of non-contradiction is a great deal more difficult to do without and provided that the law of non-contradiction holds, possibilities are always going to be intelligible. — MetaphysicsNow

The problem is that the three fundamental laws of logic are all tied together. So if the real existence of possibility causes a problem for these laws, there is also potentially a number of different ways to deal with this problem. One individual might say that possibility is accounted for by allowing an exception to the law of excluded middle. What is possible neither is nor it is not. However, another person might argue that possibility is accounted for by allowing an exception to the law of non-contradiction. What is possible both is and is not. Are you familiar with dialetheism, and dialectical materialism, which is derived from Hegel's dialectics of being? Whether one takes the position that we ought to allow exceptions to the law of excluded middle, or we ought to allow exceptions to the law of non-contradiction, to deal with the reality of possibility, makes a huge difference metaphysically. There is an even more metaphysically radical position which holds that things within this realm of possibility cannot even be identified (they cannot enter into the realm of logic because they cannot pass the law of identity), so we ought not, or "cannot" even talk about them.

Possibility does not pose a problem for intelligibility if what is possible is constrained by the laws of whatever logic you happen to prefer. David Lewis, probably the most prominent recent proponent of modal realism, considered that possibilities were real (just not actual) but even for him there were no such things as worlds in which contradictions were true. Sure, Lewis's modal realism faces a number of problems, but it does not face the problem that possibilities become unintelligible - indeed, for Lewis, his system is the only way to make possibilities intelligible in the first place.
There are a number of logics that do without the law of excluded middle but retain the law of non-contradiction (intuitionist logic, as I previously indicated). There are logics that also work with the idea that there can be true contradictions (paraconsistent logics). So-called classical logic retains both.

Clearly the real existence of possibility violates at least the law of excluded middle,

How? Are you confusing actuality with reality? They are different notions - indeed it is precisely the difference between them that modal realists like Lewis take advantage of.

Possibility does not pose a problem for intelligibility if what is possible is constrained by the laws of whatever logic you happen to prefer. — MetaphysicsNow

But possibility isn't thus constrained, this is demonstrated by the fact that mathematics always leads to infinity. That's the problem. You can produce a logical system which deals only with constrained possibilities, that is not a problem, but this logical system may not be operating with an accurate representation of possibility, because possibility may be infinite as mathematicians assume.

Here's the issue. For the sake of argument, let's assume that possibility is real. It appears to be inherently infinite, as demonstrated by mathematical principles. We could create a logic which would constrain possibility, but unless the logic is based in some true premises, these principles of constraint would be purely arbitrary. Therefore these constraints on possibility would not be real constraints on real possibility. So we must seek to represent real constraints on possibility, and this requires that we assume that there are real constraints on possibility, and we seek them for our premises. This means that the possibility which appears to us in mathematics, as infinite, cannot be considered to be real, because we have now assumed that there are real constraints on possibility.

If you want to proceed in this way, to argue against mathematical principles which accept infinite possibility, then you must do so from a principled position. We need to state some acceptable principles which would demonstrate that possibility is not infinite. This requires that we create a real, true description of "possibility", and utilize this to produce our premises. The description, if it is correct, and accurate, would indicate what possibility really is, thus constraining it to the terms of the description. Mathematics has no description of possibility, so possibility can be absolutely anything.

What I propose, as a description of real possibility, is that it is a function of time. Things in the past cannot be changed, but with respect to the future, there is real possibility. From this, we can proceed to produce a relation between future and past, whereby the possibilities of the future are constrained by the actualities of the past, thus providing the foundation for real constraint on possibility. Do you agree with this approach, or would you prefer a different description of possibility?

How? Are you confusing actuality with reality? They are different notions - indeed it is precisely the difference between them that modal realists like Lewis take advantage of. — MetaphysicsNow

No, I distinctly said "real existence of possibility", so I did not mean the "actual existence of possibility", which could quite possibly be interpreted as contradictory. For example, consider there is a chair in the other room, and I say to you that it is possible that the chair is red, and it is possible that the chair is green. These are not real possibilities, they are fictitious possibilities, made up by my mind, because there is a real description of that chair, which would exclude all other possibilities as false, unreal possibilities. There are no real possibilities concerning that chair, just an actuality, because the chair itself is an actuality These unreal possibilities are the type of possibilities which mathematics deals with, and that's why they allow infinity. They allow whatever fictitious, unreal possibilities that the mind can come up with.

An example of a real possibility is when we reference a future event which requires a human decision to bring about that event, like Aristotle's famous example of the possible sea battle tomorrow. As he describes, there cannot be any truth or falsity to that statement that there will be a sea battle tomorrow, because it hasn't been decided yet. Further, when tomorrow passes, and the event occurs, or fails to occur, we cannot look back, and say that at that prior time, one or the other was true. There simply is no truth or falsity to the statement that there will be a sea battle tomorrow. With this as a description of "real possibility", do you see how the law of excluded middle is violated? With respect to a future event, which may or may not occur, and this is the basis for my description of "real possibility", it is neither true nor false that it will occur. The dialetheists, dialectical materialists, might argue that it is both true and false, that the event will occur.

On a point on which I believe we are agreed, I think the idea that modality is a central issue for science (and I include philosophy) is correct - I even indicate on my own website that scientists like Hawking who make (made) statements to the effect that philosophy is dead are dead wrong precisely because of the implications of modality. I also think there might be an interest in pursuing the idea that the notion of human freedom might gain from analysing how specific possibilities are precipitated out of all possibilities to become actualities. However, those possible points of agreement aside, there is a lot of what you are saying that just seems plain wrong to me.
You can have a fully consistent theory of modality that retains the law of excluded middle. You can also have one that rejects the law of excluded middle, but retains the law of non-contradiction. Let's call the former kind of modal thinker a BigEndian and the latter a LittleEndian Concerning the example for Aristotle, BigEndian and LItteEndian are totally in agreement that we cannot know or decide which of the statements "There will be a sea battle tomorrow" or "There will not be a sea battle tommorrow" is true the day before the event. The BigEndian will simply insist that this is only an epistemological fact, and does not entail that neither one nor the other is in fact true. Certainly, this requires a particular brand of realism about future events, but then BigEndians (and generally speaking everyone who favours classical logic) will be a realist about most things. The LittleEndian has a (perhaps more sophisticated) view of the interplay between epistemology and metaphysics that ties together in some way what can be known/decided and what exists. There is no simple way to decide whether the BigEndian or LittleEndian is correct.
In all cases, a modal realist is not going to allow the existence of non-real possibilities: all possbilities for a modal realist are equally real, although they might not all be equally likely. This includes possibilities concerning the past (the German's might have won the Second World War) as well as the present and the future. It includes farflung fancies - for instance possibilities that I come up with on the spur of the moment like there could be a cow on the moon right now eating grass - and possibilities that are more closely anchored to actuality - the structure of benzene might not have been discovered by Kekule. Now, any modal realism is going to have an interest in making distinctions between possibilities on the grounds of their relevance to specific cases, but the basic thing they have to go on regarding what possibilities are real is the logic they accept. Modal realists who subscribe to either intuitionist or classical logic will both fall back on the law of non-contradiction. Modal realists who subscribe to paraconsistent logics might not (it depends how expansive they take the idea of a true contradiction to be).

Your points about infinity and possibility are not clear to me - modal realists of any kind can quite happily accept the idea that there are an infinite number of possibilities and that does not render possibilities unintelligible.

You can have a fully consistent theory of modality that retains the law of excluded middle. You can also have one that rejects the law of excluded middle, but retains the law of non-contradiction. Let's call the former kind of modal thinker a BigEndian and the latter a LittleEndian Concerning the example for Aristotle, BigEndian and LItteEndian are totally in agreement that we cannot know or decide which of the statements "There will be a sea battle tomorrow" or "There will not be a sea battle tommorrow" is true the day before the event. The BigEndian will simply insist that this is only an epistemological fact, and does not entail that neither one nor the other is in fact true. Certainly, this requires a particular brand of realism about future events, but then BigEndians (and generally speaking everyone who favours classical logic) will be a realist about most things. The LittleEndian has a (perhaps more sophisticated) view of the interplay between epistemology and metaphysics that ties together in some way what can be known/decided and what exists. There is no simple way to decide whether the BigEndian or LittleEndian is correct. — MetaphysicsNow

This is the ontological difference which I alluded to. The "fully consistent theory of modality that retains the law of excluded middle, also excludes what I call "real possibility". The theory of modality accepts only epistemic possibility, logical possibility. But as mathematics demonstrates these possibilities are infinite, and this give us no means for differentiating between what is physically possible, and what is physically impossible. So we have here a problem because many things which are logically possible are physically impossible. We need a way to deny this designation of "possible" to those things which are physically impossible, because they are really impossible.

From my ontology, the BigEndian 's position is based in a false premise. The BigEndian would allow that things which are physically impossible are really possible, simply because they are logically possible. I argue that there is no truth or falsity to the statement "there will be a sea battle tomorrow", because this is an ontological reality, a physical fact, rather than an epistemological fact.

The difference being that the BigEndian is committed to determinism, I am not. If it's simply a matter of us not being able to know the outcome, what will happen tomorrow, but there is a truth or falsity to it, then it is necessarily predetermined. The LittleEndian, will argue that there is no truth or falsity to this matter because it has not yet been decided, and it could go one way or the other. Of course there is no simple way to decide which is correct, that's why metaphysics is not a simple subject of study, it is extremely complicated. However, as I've demonstrated in a most basic way, the BigEndian's position is based in a false premise, allowing that impossible things are possible.

In all cases, a modal realist is not going to allow the existence of non-real possibilities: all possbilities for a modal realist are equally real, although they might not all be equally likely. — MetaphysicsNow

This is just a matter of how you define "real". I explained what I consider as a real possibility. If a modal realist premises that all logical possibilities are real possibilities, I think that this is a false premise. I think that many logical possibilities are physically impossible. Therefore it is only by changing the definition of "possible", such that it is no longer opposed to "impossible", that one can label something as "possible" which is also impossible, without contradiction. My definition of "real possibility" avoids this contradiction without resorting to such nonsense.

Your points about infinity and possibility are not clear to me - modal realists of any kind can quite happily accept the idea that there are an infinite number of possibilities and that does not render possibilities unintelligible. — MetaphysicsNow

But that's exactly the point, infinite possibility is unconstrained possibility, and this is unintelligible. So if modal realists allow infinite possibilities, then this leaves "possibility" itself as something unintelligible. Possibility is something which is infinite, and an infinite thing is unintelligible.

Possibility is something which is infinite, and an infinite thing is unintelligible.

There seems to be some element of talking past each other here between you and MetaphysicsNow. Perhaps you are right that because there are infinite possibilities we (as finite beings) cannot survey all of them at once. However, I think MetaphysicsNow is suggesting that this is to some extent irrelevant because it does not impact our abilities to entertain any specific possibility. "Possibility" is ambiguous between your two usages. For you it appears to be the sum of all possibilities. For MetaphysicsNow it appears to be just that which defines something as being a member of that group of infinite things. MetaphysicsNow is perfectly correct that possibility is intelligible if he means by "possibility" what I believe he means. You might be right that possibility is unintelligible if you mean by that that we cannot survey all possibilities at the same time. Metaphysicsnow is using the term "possibility" in one of its perhaps more usual senses, but that doesn't mean that you cannot use the term in your sense. However, in order to avoid misunderstanding, I suggest that where it is important to make the distinction between your two meanings, that you use distinct terms. So that neither one of you calls "foul" I suggest that MetaphysicsNow use the phrase "the notion of possibility" instead of "possibility" and that you use "the sum of all possibilities" instead of "possibility". You can both still use the word "possibility" to say things like "it is a possibility that I will win the lottery tomorrow, since I bought a ticket" or "there are possibilities no one has thought about yet" without risk of ambiguity, but where the claims start becoming metaphysically significant, it would help clarify both positions and all your arguments if you use the terminology I suggest. Would you both agree with that?

There seems to be some element of talking past each other here between you and MetaphysicsNow. Perhaps you are right that because there are infinite possibilities we (as finite beings) cannot survey all of them at once. However, I think MetaphysicsNow is suggesting that this is to some extent irrelevant because it does not impact our abilities to entertain any specific possibility. — jkg20

The issue though, is what type of thing is a possibility. If we cannot produce a description of what a possibility is, then we cannot distinguish between a true possibility and a false possibility, therefore whether or not a thing actually is a possibility is unintelligible. I will use "true" and "false" instead of "real" because there seems to be ambiguity with "real".

"Possibility" is ambiguous between your two usages. For you it appears to be the sum of all possibilities. For MetaphysicsNow it appears to be just that which defines something as being a member of that group of infinite things. — jkg20

I think that what is ambiguous between us is the use of "real possibility". MetaphysicsNow seems to believe that if something is logically possible, then it is a real possibility. My argument is that logical possibilities are necessarily derived from premises, and if these are false premises, then they are not true possibilities.

Further, I argue that the assumption that there are infinite possibilities is itself a false premise. And, it is this premise, which is derived from mathematics, that defines "possibility" in such a way so as to exclude "impossible". If there are an infinite number of possibilities, then nothing is impossible because an impossible thing would limit the amount of possibilities. This move excludes "falsity", because the false thing is the impossible thing. Something which is false is something which is impossible. Following this move, we now have no basis for a distinction between true and false, because the possibility of falsity has been removed. But this is itself inherently contradictory because to remove the possibility of impossibility is to remove a possibility, and leave possibilities as less than infinite. Therefore the idea of infinite possibilities is inherently contradictory, and unintelligible, because it would require excluding the possibility of impossibility, which would leave it less than infinite. So if this is really what MetaphysicsNow is arguing, it is impossible that "possibility" is what defines something as being a member of an infinite group, because this is self-contradictory, a contradictory definition.

MetaphysicsNow is perfectly correct that possibility is intelligible if he means by "possibility" what I believe he means. — jkg20

No, if MetaphysicsNow is saying what you claim, this is not perfectly correct, it is unintelligible because "infinite possibilities" is self-contradictory, so we ought to stop talking in this way. In mathematics we have infinite numbers. But when a logician takes the concept of "infinite", and applies this to the concept of "possibility" to create the premise that there are an infinite number of possibilities, the logician creates a contradiction because "impossible", by definition already limits "possible", so the logician is trying to make unlimited that which is already, by accepted definition, limited. To avoid the contradiction, the logician must give "possible" a new definition which is not opposed to "impossible". But now the logician has excluded "impossible" from the allowable lexicon, leaving us without a true definition for "possible", and without the capacity to designate something as false, impossible. This definition of "possible" is itself unintelligible because it is not opposed to impossible. It really has no meaning. being simply an undefined term.

Would you both agree with that? — jkg20

I do not agree to those terms because I think that MetaphysicsNow's use of "possible" is completely unacceptable. My argument is to demonstrate that this is an unacceptable use of the term. You propose that we each go on using the term each in our own way, with some indication to separate them, but this is a proposal to continue talking past each other. The whole point we are trying to work out, is that we need a description of what a "possibility" is, in order that we have something intelligible to work with. If we cannot agree on a description, then we continue talking past each other. If we continue talking past each other, then "possibility", therefore what qualifies as "a possibility" remains unintelligible to us.

Now you've lost me completely, since many of your own posts use modal terms like "possibile" "possibly" "might have" etc - in a way that would suggest you had some conception of what possibility is in some cases, which would mean that at least for you at least possibility is intelligible. Two examples:

But physical illness is not necessarily neurological though. That is the problem, there are many possibly factors, diet, hormones, etc.

There are many instances where John might decide to vote "Yes", but actually vote "No". He might change his mind, as you mentioned, he might forget, as we already talked about, or he might just make a mistake in marking the ballot. Notice that even a mistaken action is a very real possibility and must be accounted for.

But if you think that possibility is completely unintelligible, then given that what is unintelligible cannot be meaningfully talked about, you seem to be commiting yourself to have been talking nonsense whenever you discuss modality.

I'll have to leave you and MetaphysicsNow to fight it out, I'm afraid, and find a more classically coherent thread to follow.

In all cases, a modal realist is not going to allow the existence of non-real possibilities: all possbilities for a modal realist are equally real, although they might not all be equally likely. — MetaphysicsNow

Modal realists who subscribe to either intuitionist or classical logic will both fall back on the law of non-contradiction. Modal realists who subscribe to paraconsistent logics might not (it depends how expansive they take the idea of a true contradiction to be). — MetaphysicsNow

You made nice points. Possibilities are real to the degree that some logic, some principle of intelligibility, constrains an unformed potency. And logics suggest increasingly restrictive constraints, reaching their strongest form in possibilities that obey the LEM.

But my issue with modal realism is that it does reduce the real to the accidental. Every option that could be taken, does get taken. Probability - as some certain propensity or likelihood - is now some kind of illusion. In the infinite multiverse, we have no grounds for treating different outcomes as reflecting different propensities.

So there is a problem. Logic provides a formal structuring. It constrains an unbounded potential, a vagueness, so that it has to be - in the strongest logical form - a bivalent case of either/or. But modal realism then wants to make all accidents real. They each have their own world, or world branch.

Likelihood seems preserved in that many more of some outcomes are found than others. But that then raises the question of who actually knows this to be the case so that the events of any one world can rightfully be seen as probabilistic - actually a play of possibilities? A God’s eye view from nowhere is being smuggled in to secure this further metaphysical fact.

So while logic - as intelligible structure - does lie over events as an ultimate formal cause, we need to go a step further and throw in a finality as well. Some even higher kind of constraint must be real to complete the modal job.

And this is routinely suggested in physics. There is the principle of least action, or sum over histories, which collapses the many logically possible worlds back towards the one. Propensity becomes real because while all alternatives are real, they add or subtract in ways that further constrain the actualised outcome. We wind up back in just the one world because finality closes things. By necessity, the accidental winds up actually being restricted in its open, and even infinite, variety.

One important distinction that I haven't seen crop up in this thread is that there are conditions or states of being that are a result of individual psychology and/or physiology. A distinction between the two is hard to make; but, whereof one cannot reason through a condition (I call it a condition instead of a disorder due to the negative connotation of being "mentally-ill") thereof one can try medication...

Some interesting points, and your last paragraph is something I've posted about on my website in the past (the unexamined commitments to possibilities embedded in the use of the principle of least action, which raise questions about exactly how specific possibilities crystalize into actualities).
Concerning modal realism, and specifically the kind that David Lewis propounds, if I understand you correctly you regard a central problem with it as being its account of probability? I'm not a modal realist, but I would imagine that they would try to adopt some Bayseian notion of probability in which the beliefs concerned would be beliefs about which of the many possible worlds one is located in. Not sure whether this would work or not, however. Although it would take more argument to make a direct identification between Lewisian modal realism and quantum mechanics "many-world"ism, I believe that some have also argued that under a many-worlds interpretation, probabilities just disappear because (to paraphrase you) "everything that can happen does happen". I think I've read somewhere that a Bayseian approach combined with some kind of idea of self-locating beliefs (i.e. beliefs about which world you are in) can help with this, but I've not dug into it in too much detail. In any case, going Bayseian to save a metaphysical position certainly does invite the question about who's beliefs are concerned here, and I think you might be right that there is a tendency to smuggle in a God's eye-view hoping to pull the wool over our eyes that there is not an implicit commitment to idealism (of some kind or another).

But if you think that possibility is completely unintelligible, then given that what is unintelligible cannot be meaningfully talked about, you seem to be commiting yourself to have been talking nonsense whenever you discuss modality. — jkg20

I don't see your problem. We mention the unintelligible commonly, it is thought of as the unknown. We don't know if it's apparent unintelligible nature is due to deficiencies in our capacities, or it is inherently unintelligible itself, but we apprehend it as the unknown, and approach it as if it is for some reason unintelligible, that's why it's unknown. This does not mean that we cannot speak of it.

I outlined to metaphysicsNow, three different approaches to this sort of unknown, which we call the possible. One is to assume that the possible violates the law of excluded middle. The second is to assume that the possible violates the law of non contradiction. The third, which I called a radical metaphysics is to assume that the possible violates the law of identity, and therefore we cannot even speak of it. You have chosen this radical position.

Possibilities are real to the degree that some logic, some principle of intelligibility, constrains an unformed potency. — apokrisis

We seem to actually have some agreement on this point. As I argued, the only "real" possibilities, what I now call "true" possibilities, are constrained possibilities, therefore "infinite possibilities" does not refer to something real, and cannot be part of a true premise.

We mention the unintelligible commonly, it is thought of as the unknown.

A little like @jkg20, I'm beginning to get a little lost, since what is unknown is not commonly what is unintelligible. Supposing I don't know what my birthday present is because it is wrapped in paper. Suppose that what is wrapped in that paper is the latest iPhone. That I do not know that my birthday present is an iPhone does not make either the iPhone nor the fact that it might be my birthday present unintelligible to me (indeed I may even hope or imagine that my birthday present is an iPhone) .

Anyway, let's get back to modality:

MetaphysicsNow is perfectly correct that possibility is intelligible if he means by "possibility" what I believe he means. — jkg20


No, if MetaphysicsNow is saying what you claim, this is not perfectly correct, it is unintelligible because "infinite possibilities" is self-contradictory, — Metaphysician Undercover

jkg20 said of me, more or less, that when I use the word "possibility" in the abstract, it just stands for "criteria for what is possible". That's pretty much correct, and I do not see how it commits me to the unintelligibility of possibility or possibilities. The criteria will vary in varying circumstances - sometimes we will be interested only in what is physically possible (i.e. the criteria will include the idea that whatever is possible has to conform with the known laws of nature). At other times, perhaps when writing science fiction, we may want to think beyond those constraints, but still wish to insist that what we are imagining is a possible future, and in that case our criteria would be limited to excluding only logical contradictions (at least, to exclude obvious logical contradictions, some logical contradictions can be deeply buried). In both kinds of cases, laying down the criteria of possibility allows for an indefinite number of perfectly intelligible possibilities. Perhaps it also allows for an infinite number of possibilities, I don't know, it doesn't seem to me to matter much one way or another.

I think I've read somewhere that a Bayseian approach combined with some kind of idea of self-locating beliefs (i.e. beliefs about which world you are in) can help with this, but I've not dug into it in too much detail. — MetaphysicsNow

Yeah. My distant memory is that Lewis relies eventually on counterpart theory and resemblances. So each of us is individual in our own world. And then there are all the other worlds where I am living a life that is only insignificantly different.

There is no actual identity - as we each represent at least one counterfactual difference in existing in a different world. But we would tend to formulate the same (Bayseian) laws of probability through sharing the near enough identical experiences.

Coin tossing would best be explained by a rule of chance, for instance. We would not resemble the selves that lived in the worlds where every coin toss ever experienced always came up heads.

So causation can be reduced to a subjective ascription. Nothing is either objectively chance or determined, you just happen to be located in a world that either looks that way or it doesn't.

But that's why I prefer a constraints-based ontology where both material spontaneity, and its formal limitation, are real things. It does require then a "weird" view of causality. But physics already has had to accept just that with the finality embedded in the principle of least action. Nature does sum over all of its possible histories to tend towards some optimal trajectory. The alternatives have to really exist, in some sense, so that they can count as that which is (mostly) the actually unactualised.

A little like jkg20, I'm beginning to get a little lost, since what is unknown is not commonly what is unintelligible. Supposing I don't know what my birthday present is because it is wrapped in paper. Suppose that what is wrapped in that paper is the latest iPhone. That I do not know that my birthday present is an iPhone does not make either the iPhone nor the fact that it might be my birthday present unintelligible to me (indeed I may even hope or imagine that my birthday present is an iPhone) . — MetaphysicsNow

It's no wonder you're getting lost, you're inverting what I said. What I meant is that we speak of the unintelligible as an unknown. This implies that the unintelligible is an instance of the unknown, it does not mean that all unknowns are unintelligible. Therefore, that you provide an example of an unknown which is not an unintelligible, is really irrelevant, it just means that you misunderstood what I said.

jkg20 said of me, more or less, that when I use the word "possibility" in the abstract, it just stands for "criteria for what is possible". That's pretty much correct, and I do not see how it commits me to the unintelligibility of possibility or possibilities. The criteria will vary in varying circumstances - sometimes we will be interested only in what is physically possible (i.e. the criteria will include the idea that whatever is possible has to conform with the known laws of nature). At other times, perhaps when writing science fiction, we may want to think beyond those constraints, but still wish to insist that what we are imagining is a possible future, and in that case our criteria would be limited to excluding only logical contradictions (at least, to exclude obvious logical contradictions, some logical contradictions can be deeply buried). In both kinds of cases, laying down the criteria of possibility allows for an indefinite number of perfectly intelligible possibilities. Perhaps it also allows for an infinite number of possibilities, I don't know, it doesn't seem to me to matter much one way or another. — MetaphysicsNow

What you describe as the "criteria for what is possible", I find to be unintelligible. It seems completely arbitrary. You seem to be saying, that with varying circumstances, the criteria for what is possible also varies. How can this be the case? We've identified a type of thing which is "a possibility" and we want to know how to recognize a possibility when we apprehend one, so we need some clear criteria for recognition, and identification. You say, depending on the circumstances, the criteria varies. How is this any sort of realistic way to recognize or identify something, to say that it always appears differently, it fulfills different criteria, in different circumstances? What kind of criteria is this? Can't we find something consistent from one instance of possibility to the next, such that we know we are dealing with the same type of thing, a possibility? Or do we just make up the criteria, however we wish, according to what we want from the circumstances? That doesn't make sense, because we would be very likely to designate something which is really impossible, as possible, if we do not have the proper criteria. Since it is possible that we could confuse the impossible with the possible, then it is impossible that the criteria is arbitrary, as you seem to imply. Therefore there must be some real principles which could be used to distinguish the possible from the impossible in each and every circumstance. Don't you agree?

I suggest we start with very simple and straight forward criteria. Whatever is not impossible is possible. Do you agree? If something, for whatever reason, is determined as impossible we know that it is not possible. Likewise, if we know that something is not impossible then we know that it is possible. If we do not know whether or not it is impossible, then we do not know whether or not it is possible. Do you agree?

If something, for whatever reason, is determined as impossible

This is precisely the issue in reverse though - what are the criteria for impossibility? Are we talking about physical impossibility, logical impossibility.... Each will have different criteria presumably, just like "possibility" under my contention.

And just to be fair to myself, you did identify the unintelligible with the unknown in this comment:

....it is thought of as the unknown

I don't know who thinks of it as the unknown, but not me, and I gave you a reason why. You may have meant to say that being unknown is a necessary but not sufficient condition for being unintelligible, but thinking of one thing as another is (in usual parlance) to equate the two things in thought, which in this case would be to take being unknown as a necessary and sufficient condition for being unintelligible.

Yes, counterpart theory - perhaps the most extreme form of nominalism I've come across. When I read Lewis (like you, years ago) I was reminded of Hume's remark about Berkeley being totally irrefutable but utterly unconvincing.

I think we are largely in agreement on many points, although I do have a couple of questions for you.

One of the "possible" positions that niggles at me is that the principle of least action may simply be a heurestic device for balancing energy equations, and thus has no real ontological commitments. My response to that is that there are no grounds for treating the PLA any more or less heuristically than any other law of nature, so that there is probably some question begging going on behind the reply, but that seems a little limp-wristed. Perhaps you have a better line of response?

As regards the constraints based ontology you talk about, could you expand a little on this and specifically what you mean by "material sponaneity" and "formal limitation"? Examples always help me, but granted examples can sometimes be misleading and fail to capture nuances. Do you regard the formal limitations as capable of evolution, or are they fixed and immutable?

whereof one cannot reason through a condition

I think the motivation behind my position is that where the condition involves action, it is always possible to reason through it (even if doing so requires emotional support etc). That being so I'd be committed to saying that there are no conditions of the type we are discussing that cannot be reasoned through.

Of course, a line of approach we've not yet considered is the later Wittgensteinian one that would treat the word "possible" like the word "game" - no one single definition is going to link all intelligible uses of the word. In any given case we can unpack the word "possible" and frame it in other terms (for instance as counterfactual conditionals which hold the laws of nature fixed, or as counterfactual conditionals that hold only the law of contradiction fixed, etc etc) but there is no single criterion or rigid set of criteria that all intelligible uses of the word must meet. Sure, anything that is not impossible is possible, so whenever we use the word "possible" we could probably replace it with "not impossible" (although there are probably nuanced examples where the choice between the two would change what the speaker expressed about his own opinions) but at least in terms of formal modal logic, to state that what is possible is not impossible is just an empty tautology.

I think the motivation behind my position is that where the condition involves action, it is always possible to reason through it (even if doing so requires emotional support etc). That being so I'd be committed to saying that there are no conditions of the type we are discussing that cannot be reasoned through. — MetaphysicsNow

Hard to say. There are some conditions that are hard to address through therapy alone. OCD seems to be one of them that is best treated with psychotherapy and medication, from what I surmise.

It's the fall back to medication - and specifically justifying that fall back by the argument that the actions are simply not under the sufferers control - that bothers me. I agree 100% that getting OCD under control can be hard and that sufferers might need a great deal of emotional and practical support. However, the medications that are prescribed in these cases are antidepressants which are not harmless and there are arguments to be made that in many cases the OCD symptoms are to be preferred to the side-effects of taking antidepressant drugs. But in any case, the philosophical issue here is largely independent of our sympathy for OCD sufferers, and concerns the metaphysical presuppositions behind the notion of self-control and (as Norman Malcolm put it) the conceivability of the mechanicistic stance in regard to human action.

Well, we can be prejudiced against antidepressant drugs or we don't have to. I see no issue taking antidepressant drugs if there is a clinical need that needs addressing Do you?

It's the fall back to medication - and specifically justifying that fall back by the argument that the actions are simply not under the sufferers control - that bothers me. — MetaphysicsNow

Well, I tend to believe that medication in combination with therapy leads to the best prognosis of remission. If one so chooses to not take medication, then that is a personal choice, though I don't understand the issue with taking medication, if there is a need.

I agree 100% that getting OCD under control can be hard and that sufferers might need a great deal of emotional and practical support. However, the medications that are prescribed in these cases are antidepressants which are not harmless and there are arguments to be made that in many cases the OCD symptoms are to be preferred to the side-effects of taking antidepressant drugs. — MetaphysicsNow

Well, yes. Ideally, if we could we would want to start therapy first instead of medicating an individual. However, due to the issue of cost and the powerful pharmaceutical lobby (at least here in the US), people are referred to psychiatrists instead of psychologists. Do I think that needs to change? Sure, just that the politicians in power assume in part your position in that depression, anxiety, phobias are individual problems, not social ones.

But in any case, the philosophical issue here is largely independent of our sympathy for OCD sufferers, and concerns the metaphysical presuppositions behind the notion of self-control and (as Norman Malcolm put it) the conceivability of the mechanicistic stance in regard to human action. — MetaphysicsNow

I don't think self-control will solve the issues a schizophrenic or bipolar individual might experience. To say that would be idiotic.

I don't think self-control will solve the issues a schizophrenic or bipolar individual might experience. To say that would be idiotic.

Why would it be idiotic? I'm certainly not suggesting that people with schizophrenia or bipolar syndrome can just "snap out of it" all by themselves: that would be idiotic.

Why would it be idiotic? — MetaphysicsNow

Well, I have heard of only one case in my lifetime for whom their schizophrenia was treated via psychotherapy. Some people decide to live with their condition. But, the important thing is that they know that their thoughts are disorganized or in a constant state of paranoia. Keep in mind that these people we are talking about feel very strongly about what they're experiencing. In other words, it's very easy to get lost in the void of turmoil and chaos of an (I wince using the following word) "ill" mind.

Schizophrenia, which I can pontificate about here since I was once diagnosed as a schizophrenic, is primarily an anxiety disorder gone wild. That is to say that the schizophrenic (in most cases of the paranoid subtype) lives in a constant state of fear. Now, the issue is that the desire to control oneself is imbued by persecutory beliefs and the whole list of other disorganized thinking that a schizophrenic experiences. In other words, self control mandates an objective view of oneself in relation to the world, which in most cases can only be provided through a therapist or (yes) trough self therapy or put more bluntly "reality-testing". However, if the world of a schizophrenic or similarly any other disorder by extension is disorganized or twisted by said disorder, then the effort for self control will be mostly futile (I'm talking about people who authentically believe the voices they hear, which are 90% of the homeless population for your information). Therefore, the absolute need for medication to balance the 'flux' and then proceed with therapy.

Just to go to the logical conclusion of my last post...

In many cases people with disorders (read distress) shut off from the world and don't want to have to do anything with it. To be quite honest, as a person who has suffered, I completely understand the desire to cut oneself off from the world and fantasize or indulge in bad habits or obsessing over trifle stuff. Even people without mental disorders live in a manner that shuts themselves off from the concerns of the world or their neighbors and friends. It's just easier that way to live in our modern society.

My response to that is that there are no grounds for treating the PLA any more or less heuristically than any other law of nature — MetaphysicsNow

It's off topic, so I'll keep it short, even though it is the topic I'm focused on currently.

Even if all laws are heuristic, the PLA is a principle and so distinct in being foundational to laws generally. There seem to be three such guiding principles - the PLA, the cosmological principle, and the principle of locality. My particular interest here is how they fit together.

The PLA becomes truly mysterious and non-local in quantum physics. The path integral or sum over histories formalism suggests events take the least action path over all their possible states. Quantum gravity would (likely) have to see even time and space as emergent in this manner.

A nice intro is Metaphysics of the Principle of Least Action, Vladislav Terekhovich - https://arxiv.org/pdf/1511.03429.pdf

As regards the constraints based ontology you talk about, could you expand a little on this and specifically what you mean by "material sponaneity" and "formal limitation"?

Do you regard the formal limitations as capable of evolution, or are they fixed and immutable? — MetaphysicsNow

Again, keeping it short, I am arguing for a holistic metaphysics in opposition to the usual reductionist story. So I am arguing for an Aristotelian "four causes" or hylomorphic understanding of Being. As well as the bottom-up constructing causes of efficient/material causality, there is the top-down constraining causes of form/finality.

This is a systems science or hierarchy theory approach. And with CS Peirce, it becomes a semiotic approach where the top-down becomes understood as the informational aspect of reality, the bottom-up as the material or dynamical aspect of reality.

Peirce added the further critical logical wrinkle of understanding reality as a process of rational development - what we would call today, order from chaos or self-organising criticality. The thermodynamic or condensed matter approach to physical structure. So Peirce added Vagueness as a category of logic, a ground of being. A system crisply organised according to the four causes could have the appropriate kind of "nothingness" from which it could actually arise.

So this all cashes out as a general story where reality is the result of the development of constraints that organise a systems degrees of freedoms (and organises them in the precise evolutionary fashion that causes those freedoms, that resulting play of events, to cause the whole system itself to stably persist).

So it is an autopoietic story, a story of ontic structural realism, a story of dissipative structure, to name-check a few of the expressions of the general idea that might be familiar.

To make the contrast with reductionism - and nominalism, atomism, mechanicalism, etc - the systems view does see laws as "merely" the expression of collective behaviour. Peirce called them habits. But then the collective behaviour exerts the constraints that shape the parts making the system. So there is a cybernetic loop. There is feedback that limits the freedoms of the system's events so that they become the kind of thing that are the right stuff to keep the general show going.

From here, it is easy to see why symmetry principles become the governing factor of existence - hence the cosmological principle. At an almost Platonic level, there are logical forms that chaos cannot avoid falling into. For instance, a vortex or whorl is found everywhere in nature where there is dissipation to be done. It is the least action structure. Similarly for fractal branching.

And this is where logic comes in - as an unavoidable form. Logic expresses a least action principle in that is represents a maximal breaking of states of vagueness or uncertainty. It represents the symmetry-breaking which is a binary yes or no, true or false, present or absent.

And quantum interpretations are now picking up on this angle. Wheeler put it nicely with his "it from bit" papers...

This report reviews what quantum physics and information theory have to tell us about the age-old question, How come existence?

No escape is evident from four conclusions: (1) The world cannot be a giant machine, ruled by any preestablished continuum physical law.

(2) There is no such thing at the microscopic level as space or time or spacetime continuum.

(3) The familiar probability function or functional, and wave equation or functional wave equation, of standard quantum theory provide mere continuum idealizations and by reason of this circumstance conceal the information-theoretic source from which they derive.

(4) No element in the description of physics shows itself as closer to primordial than the elementary quantum phenomenon, that is, the elementary device-intermediated act of posing a yes-no physical question and eliciting an answer or, in brief, the elementary act of observer-participancy.

Otherwise stated, every physical quantity, every it, derives its ultimate significance from bits, binary yes-or-no indications, a conclusion which we epitomize in the phrase, it from bit.
http://cqi.inf.usi.ch/qic/wheeler.pdf

So it boils down to the idea that logic - as a Platonic-strength limitation on uncertainty or vagueness - can conjure existence into substantial being simply by applying its PLA-style constraints on naked or chaotic possibility.

Lewis and other nominalists/reductionists take a different view of possibilia in treating them as already definite and crisp degrees of freedom. Reality is a statistical ensemble of already concretely bounded alternatives. That assumption is explicit in modal realism's talk of "worlds". And the ensemble view is also what leads many to a Many Worlds Interpretation of QM.

But I am taking the alternative holistic view where possibility is more basic than that. It starts out as pure unformed potential - an indeterminate and unsubstantial vagueness. Then it starts to develop lawfulness or order as all its unlimited variety gets sieved according to a unifying principle of least action. You get a world that evolves into concrete form as it dissipates its early confusion and erases whole constellations of possibilities with every now definite physical event.

If my eye absorbs that photon from a distant star a billion light years away, then that is it. The event fixes a history. Time has been added to in a concrete fashion that forever limits any alternative result.

So we end up with just the one world creating itself by erasing possibilities. You don't have a modal realism/MWI story of whole new worlds being created every time there is a possible logical fork in the road. Instead, localised events are a non-local or contextual collapse of every other alternative.

The mystery of the PLA is that all the other alternatives did weigh in the balance. They were real in the sense that they really were there in a way that just got eliminated in a systematic and forever fashion. Until my eye did decohere that photon, the Universe was that fraction more uncertain. The alternative outcomes still existed as a fuzzy set of freedoms. And QM gives you a way to measure that kind of concrete possibilia. You can see it as a "block" of unrealised choices - the wavefunction.

Anyway, a short post has grown long. These are exciting times for metaphysics. :)