It is not sufficient that determinism be false for free will to be possible according to libertarians. — Pierre-Normand

Why not? I think that if free will is inconsistent with determinism, then the demonstration that determinism is false is exactly what is required to demonstrate that free will is possible. A and B cannot both be true. A is false therefore B is possible. I know that this does not necessitate free will, but you're talking about the possibility of free will here. The problem is that free will is fundamentally inconsistent with necessity. So free will can only be accurately related to possibility, not necessity. it would be self-contradictory to say that free will is necessary.

Imagine, someone says "prove to me that libertarian free will is a reality". Then you attempt to make an argument which would produce the necessary conclusion. That would mean that the person that you are presenting the demonstration to would have no choice but to accept the conclusion of the reality of free will. But that instance of having no choice would be impossible if free will is the reality. Therefore, when an anti-free-willie asks a free-willie to prove the reality of free will, it's a loaded question, because if free will is the reality this is fundamentally impossible. Sure, the air is cold and thin at the top of the mountain, but enjoy the view, there is no reason to come down until some kind of need makes the decision to descend "necessary", as the means to the end.

Why not? I think that if free will is inconsistent with determinism, then the demonstration that determinism is false is exactly what is required to demonstrate that free will is possible. — Metaphysician Undercover

It might be that free will is impossible if either determinism or some other X is true. A demonstration that determinism is false isn’t a demonstration that this other X is false, and so not a demonstration that free will is possible.

It might be that free will is impossible if either determinism or some other X is true. — Michael

This is a misleading statement, because if it "might be", means it is still possible. So "it might be impossible" means that it is possible. To say that it is "impossible" rather than that it is possible that it is impossible, would require another demonstration to show the required necessity. if determinism is shown to be necessarily false, how would you proceed with that demonstration, when the only other premise we have is that determinism is inconsistent with free will? Since these are the only two premises, the appropriate conclusion is that free will is possible.

A demonstration that determinism is false isn’t a demonstration that this other X is false, and so not a demonstration that free will is possible. — Michael

We have two premises. One is that determinism and free will are incompatible, the other is that determinism is false. From these two we conclude that free will is possible. There is no "other X", so your premise concerning "other x" is irrelevant. If there is something else, "other x", which forces the necessity that free will is impossible, this would be a completely different argument. And until that "other X" is identified and shown logically to make free will impossible, the conclusion from the other two premises, that free will is possible, stands. From the premises stated we can conclude that free will is possible, and "other X' has not been shown to be relevant.

Then as an example, free will (according to the libertarian) is incompatible with both determinism and quantum indeterminacy. A demonstration that quantum indeterminacy is true is a demonstration that determinism is false, but not a demonstration that free will is possible. Free will requires that there is some third mechanism (e.g. agent-causation) for action, and the libertarian's task is to make sense of such a thing and show that such a thing is possible.

Then as an example, free will (according to the libertarian) is incompatible with both determinism and quantum indeterminacy. — Michael

OK, this would be acceptable. but this leads to a further problem in defining "libertarian free will". You now have two conditions stated here: #1 incompatible with determinism, #2 incompatible with quantum indeterminacy.

I believe that free will is incompatible with determinism, which is consistent with condition #1. I also believe that free will is compatible with quantum indeterminacy and this is inconsistent with condition #2. So now we have two conceptions of "free will" which are both incompatible with determinism. I always thought that my conception of "free will" is compatible with so-called "libertarian free-will", but according to your stated conditions, it is not.

Are you able to help me to expose the difference between these two conceptions of "free will" which are both incompatible with determinism? Can you explain to me what are the features of the libertarian conception which make it incompatible with quantum indeterminacy, and in exchange I will explain why my conception avoids this incompatibility?

Free will requires that there is some third mechanism (e.g. agent-causation) for action, and the libertarian's task is to make sense of such a thing and show that such a thing is possible. — Michael

Agent causation is not a problem for my conception of free will, and it ought not be sufficient to impose condition #2 on the libertarian conception, but maybe you can demonstrate otherwise. The "agent" involved is an immaterial act, as described by classical dualist metaphysics, and commonly known as the soul.

Material existence occurs at the present as time is passing. It is what "is", implying "now" which is commonly known as the present. The immaterial cause is always prior to, i.e. in the future of the present "now", so it is never observable to us. It is known only by its effects which manifest at the present. As time passes, the immaterial cause may act as "agent" to influence what unfolds as observable material existence, at the present.

For further explanation, consider this. The principles of quantum physics apprehend a shortest possible period of time, which is represented as the Planck length. Now suppose two material, or physical states which are supposed to be separated by a Planck length duration of time. These are the describable situation at T1, and the situation at T2. These two situations are not the same, so something must happen in that short duration of time to "cause" a difference between the the situations.. But whatever happens in that time between T1 and T2, it cannot be referred to as a material, or physical occurrence, because it occurs during a period of time which the principles of quantum physics dictate that a material or physical change is impossible. Therefore, the change which happens between T1 and T2 is an immaterial, or nonphysical change. This is where the immaterial, or nonphysical "soul" may be active, as an agent, and influence what becomes at T2, from what was at T1.

I described the immaterial soul s acting "in the future of the present moment" because we measure time as it passes, so all measured time is in the past. Therefore, as we attempt in our experimental endeavours to produce a shorter and shorter period of time, what we are really doing is reducing the amount of past time, within the measured duration, to get a more and more accurate pinpoint positioning on "the present moment". The pinpoint positioning appears to be impossible, hence the limitation of the Planck length, and so the Planck length substitutes for the pinpoint position of the present, as "the infinitesimal". However, there is necessarily change which occurs during this time period (the infinitesimal) which serves by substitution as "the present moment", as demonstrated logically above. This is the change which occurs between T1 and T2, as these are different situations. This activity must be apprehended as occurring prior to the present, outside (as prior to) the boundaries of "measured time", which is past time. So any agent which acts to cause change within this infinitesimal time period, must be acting in the future of the present moment.

Are you able to help me to expose the difference between these two conceptions of "free will" which are both incompatible with determinism? — Metaphysician Undercover

If our actions are the consequence of quantum indeterminacy then they are the result of random chance, not free choice.

If our actions are the consequence of quantum indeterminacy then they are the result of random chance, not free choice. — Michael

Chance is not properly a cause, it is simply a descriptive term. Therefore "chance" in the context of quantum indeterminacy cannot cause actions, and no actions can be said to be "the consequence of quantum indeterminacy" in that way, as if indeterminacy had caused these actions. "Chance" and "indeterminacy" are how we describe these actions, not the cause of the actions.

However, the real and natural situation, which is referred to by that phrase "quantum indeterminacy", provides a situation where the free willing agent can act in a manner which is not dictated by the laws of determinism (therefore not compatible with determinism). I described this relationship between the possible free willing "agent" and the principles of physics (laws of determinism), and how what is understood by quantum mechanics allows that the free willing "agent" is logically a real possibility, in the post above.

That’s fine. The point is that showing that determinism is false isn’t showing that free will is possible. The libertarian needs to explain what free will requires (e.g. an immaterial soul in your example) and that these requirements are possible.

The libertarian needs to explain what free will requires (e.g. an immaterial soul in your example) and that these requirements are possible. — Michael

Well that's not true at all. Any stated proposition has the possibility of being true. Stating requirements only limits the possibilities. So, for instance we might start by stating the requirement that the proposition cannot be self-contradictory, and this requirement would exclude some propositions as impossible (necessarily not true according to that requirement).

There is a number of ways which we can proceed toward knowledge in cases of possibility, the above mentioned way would be the process of elimination, eliminating the impossible. That something is impossible is the highest degree of certainty, or necessity, which we can obtain in cases of possibility, but it is still not perfect, or absolute, because the certainty obtained relies on the truth of the stated requirement. So by the above mentioned example, the requirement of non-contradiction, if this requirement were not itself true, it would provide a false certainty.

Another way we can proceed toward knowledge in cases of possibility is to determine probability. And just like the way that the process of elimination depends on the stated requirements, this way depends on the principles deployed in the statistical analysis.

In all cases of understanding possibility, possibility is taken for granted. It need not be demonstrated, as you claim, for the reasons I explained earlier. To demonstrate logically the reality of possibility, would render it as necessary, and that would be self-refuting. So you're assertion here, as to what the libertarian must show, is to ask the loaded question I mentioned earlier. You might argue that to take possibility for granted is to assign it a sort of necessity, and that would be self-refuting, but that is a different type of "necessity" than the logical necessity which you are asking for in your request for requirements.

John claims that humans can run at 30mph.

Jane claims that humans cannot run at 30mph because the fastest a human can run is 25mph.

Joe demonstrates that humans can run at 27.5mph.

Has Joe demonstrated that humans can run at 30mph? No.

John claims that humans can make free choices.

Jane claims that humans cannot make free choices because all actions are the deterministic consequence of some prior state.

Joe demonstrates that some actions are the indeterminate consequence of some prior state.

Has Joe demonstrated that humans can make free choices? No.

John claims that humans can run at 30mph.

Jane claims that humans cannot run at 30mph because the fastest a human can run is 25mph.

Joe demonstrates that humans can run at 27.5mph.

Has Joe demonstrated that humans can run at 30mph? No. — Michael

That humans can run at 30mph remains a possibility.

John claims that humans can make free choices.

Jane claims that humans cannot make free choices because all actions are the deterministic consequence of some prior state.

Joe demonstrates that some actions are the indeterminate consequence of some prior state.

Has Joe demonstrated that humans can make free choices? No. — Michael

Libertarian free will remains a possibility. What's your point?

Libertarian free will remains a possibility. What's your point? — Metaphysician Undercover

That needs to be demonstrated. Disproving determinism isn’t sufficient.

I explained why possibility is taken for granted, rather than demonstrated logically. To demonstrate it logically would make it necessary, and this would be self-contradicting, self-refuting. You might inform yourself by rereading my replies. You ask what I called the "loaded question".

Imagine, someone says "prove to me that libertarian free will is a reality". Then you attempt to make an argument which would produce the necessary conclusion. That would mean that the person that you are presenting the demonstration to would have no choice but to accept the conclusion of the reality of free will. But that instance of having no choice would be impossible if free will is the reality. Therefore, when an anti-free-willie asks a free-willie to prove the reality of free will, it's a loaded question, because if free will is the reality this is fundamentally impossible. Sure, the air is cold and thin at the top of the mountain, but enjoy the view, there is no reason to come down until some kind of need makes the decision to descend "necessary", as the means to the end. — Metaphysician Undercover

The point which you do not seem to grasp, is the relationship between possibility and free will. These two are tied necessarily by logic, such that if there is such a thing as possibility, then there is the capacity to choose, therefore free will. Asking someone to demonstrate "the possibility of...", is to ask that person to prove the reality of free will. This is impossible for the reasons explained, therefore we take possibility for granted, without proof. So your insistence, that the proposition "Free will is possible" must be demonstrated as necessarily true, is to pose the loaded question, to ask the free-willie to refute one's own position.