Hypothetically, science proves free will isn't real

[Edwardo Piet]

1) 'Predetermined' by what?

By the one causal chain of prior causes in this one possible universe. Predetermined by causality.

If one state of things X determines a new state of things Y, and had X been different, so would Y, then you are not talking about a necessary causal history. You are talking about a contingent and determined causal history which you are irrationally proposing as a necessary and determined one.

What do you mean irrationally? The future is determined from the past, cause and effect. That makes sense if there is only one possible future.

If there is only one possible future then that future is necessary. If that future is fully predetermined by prior causes then that future is indeed contigent upon those prior causes. But that's what it means to have one physically possible predetermined future predetermined by prior causes.That's what it means to have one existential reality of cause and effect.

If however, you maintain that the state of things X determines a new state of things Y, and a different X is a logical impossibility (not merely a historical impossibility), then you ARE talking about a determined AND necessary causal history.

I'm not talking about logical possibility or impossibility. That's why I said I define determinism as "in any given moment there is exactly one physically possible future".

2) I don't see how you can discuss well the role free will might play in determining action when we can't even discuss well the details of determining action in general.

None of it is relevant if you think free will is something beyond causality and special and something that isn't compatible with determinism. And it's not relevant if you think free will is compatible with determinism either: because then we're in an agreement, I also think a free will compatible with determinism exists. I just don't think it's worth calling "free will". So that would be another conversation.

rememberWhen I say "determinism" I am talking only about the definition of determinism that I defined for you. All this talk about other ways to define it isn't doing either of us any favors because I am still trying to get a simple "yes" or "no" to my question "Do you accept my definition that determinism is the belief that "in any given moment there is exactly one physically possible future".

And also, everytime you say "free will" or "determinism" it makes no sense to me until I actually know what kind of free will you are talking about and until I know if you accept my definition of determinism.

When I make a premise that is where I am starting. If I don't know if you even accept that premise then when you talk about all these details I don't even know if you have agreed to define them the way I have or not.... and if you haven't and you haven't defined your own premises and definitions then we're both just talking past each other.

4) In determinism, what determines the one physically possible future from among the several metaphysically possible futures? Are there metaphysically possible futures? Doesn't that seem like an important question to ask?

Not really it's still just avoiding the basic question.

Okay here's two things in response to it though, I'm not going to ignore it:

1. What would a "metaphysically possible future" even mean opposed to a physically possible one?

2. As far as I know metaphysics is about ontology, it's about being and it's also about "physics beyond physics", it's about the philosophy of physics.... I'm literally saying there is only one physically possible future in every physical way. This includes metaphysical. If you believe in immaterial non-material reality I am saying there is only one immaterial non-physical possible future too. I'm simply saying that there is ONE reality with one unbroken causal chain that connects causes and effects leading to THE..... one possible future.

Look, if my own words suck at explaining I'll give you Wikipedia:

Determinism is the philosophical doctrine that all events transpire in virtue of some necessity and are therefore inevitable. Traditionally, the view relies on strict notions of causality, and most philosophical arguments in its favor have attempted at clear definitions of cause and effect as a basis for the belief that determinism is true. Notably, the idea that the past choices of seemingly rational agents could have been performed differently - or even the idea that the future decisions of such agents will turn out to be other than what they will - is usually challenged under this view. Thus, the "problem" of free will - or the idea of free will as being an "illusion" - often arises as a result of the main claim made by determinism, that is, that the past, present, and future is identifiable with an essentially unbreakable chain of circumstances of which no single link in such a chain could possibly be avoided or altered.

So do you believe free will is compatible with determinism or not?