I am supposing that the details that went into making the prediction are known. Ned has every reason to believe the prediction, there is no reason to doubt it. It is simply the case that Ned chooses contrary to the prediction. It would be strange, would it not, if some magical events transpired to guarantee that Ned's choice was always consistent with the prediction? And that's the point, if we bar these magical occurrences, Ned can choose to act contrary to the deterministic prediction. But that should not be possible if determinism is true.

And if you are talking about me specifically, I do not lack a reason to believe the prediction, I concede that the prediction should be correct if determinism is true. However, given that the prediction cannot be correct if Ned acts contrary to it, I conclude that determinism is false. I do not see how that is an "argument from ignorance." Unless you are saying that I do not have all the information that is contained in such a prediction, and in that case you are correct, I do not, but I do not see what impact that has on the thought experiment. The fact remains that, in consideration of the prediction, Ned can always choose to act in opposition to it.

Right, the contradiction is the paradox that the thought experiment expresses. Ned's immediate actions can be predicted.. if determinism is true, they should correctly predict how he should act. However, there seems to be no reason Ned could choose not to follow the prediction, and were he to act otherwise, he would falsify the prediction. Because determinism leads to this paradoxical conclusion, it must be false. That is what I am arguing.

@Philosophim @wonderer1 @Bob Ross

So there is what Ned Block has characterized as the "Harder Problem of Consciousness." This speaks to Philosophim's point about experiencing other consciousnesses.. the problem as I understand it is: how can I know what it's like to be you, without actually being you. The physicalist rejoinder may be: well the brain stuff is the same, so the mental states must be the same.. but the brain stuff is only approximately the same, not exactly the same, and the difference in brain states means different mental states, and these mental states are simply not accessible to another, at least, not in an "experiential" way.

David Chalmers states the hard problem thusly: "there is no question that experience is closely associated with physical processes such as brains. It seems that physical processes give rise to experience, at least in the sense that producing a physical system with the right physical properties yields corresponding states of experience. But how and why do physical processes give rise to experience? Why do not these processes take place "in the dark"..." (Chalmers, Consciousness and its place in Nature).

In other words, what is it about this arrangement of physical matter and energy that allows consciousness, and how is it different from some other assortment of physical matter and energy that does not allow consciousness? That is, if we think consciousness arises from a physical substrata, what about that physical substrata gives rise to consciousness?

One of the papers I included in my original post does go into what is known as the "Halting Problem" - a problem in computer science proposed by Alan Turing. This is what I take to be your objection to the thought experiment. And, I agree that the situation can be formulated such that a self-referential issue arises. However, all I need for the thought experiment to be effective as an argument against determinism, is a situation where there is no self-referential issue, but a paradox remains anyways.

In the original scenario as I have described it, Ned reads the printout, but he only reads a part of it. And, importantly, he does not read a part of it where he is reading the printout -- that would be self-referentially problematic. Because there is no self-referentially in the parts of the printout that Ned does read, there is nothing necessarily theoretically vicious about Ned reading some parts of the printout.

1. With sufficient information about Ned’s internal states and sufficient information about the surrounding environment, Ned’s immediate actions could be predicted.
2. There is sufficient information about Ned’s internal states and sufficient information about the surrounding environment.
3. Therefore, Ned’s immediate actions can be predicted.

I suppose we could stipulate that Ned has enough information about his immediate environment to make an accurate prediction about how he will act. It doesn't really concern us whether this sort of information can, as a matter of practicality, be acquired; the concern is whether in principle, if this information were acquired, could Ned act in opposition to it. And the answer to that seems to be yes.