Maybe, but you kind of avoided my question (indeed, you cut it out of your quote).

So, is my point correct or not? If a person believes that A1 is valid, that all the premises are A1 are true, and tries the strategy mentioned in the quote, he still can’t rationally avoid the conclusion. Agreed?

Not all forms of materialism embrace eliminativism.  Some materialists believe that consciousness does exist and that it’s an emergent property.

I clearly exist in some relevant sense if I think or experience anything at all (illusions or otherwise), regardless of my ontology.  You almost seem to be using “existence” in some specialized sense that I am not using, since the “existence” statement I’m using doesn’t take much of a stance with philosophy of mind.  Descartes himself said, “But I do not yet have a sufficient understanding of what this ‘I’ is, that now necessarily exists.”  Still, whatever I am, I can be certain that I exist.  It is irrational for me to consider my nonexistence epistemically possible, for if I had any beliefs at all, then I would exist.  The type of existence I have in mind is such that if x has any experiences or mental states at all (such as believing that one exists) then x exists.  It would be horrendously irrational of me to deny my own existence, and for me to deny my own existence requires that I exist.

Again, the statement “I exist” isn’t presupposing any particular metaphysical view, not even the rejection of materialism.  It is not weakly epistemically possible for me at least that “it is not the case that I exist,” thanks to cogito ergo sum.  Thus the disjunction “I exist or it is not the case that I exist” provides a counterexample to the claim, “a counterexample to "at least one of the disjuncts is true means that all the disjuncts are at least weakly epistemically possible.”

But perhaps we can think of another example of a disjunction that contains only one disjunct that is weakly epistemically possible.

“I am experiencing qualia or I am not experiencing qualia.”

Here I’m using qualia in the broad sense that just means experience, e.g. the experience of feeling pain or the experience that something appears to be black to me.

It’s very easy to define “married bachelor,” e.g. “a married man who is unmarried.”  Such a thing is logically impossible, but we can define it nonetheless.  “There is a married bachelor or there is not a married bachelor” is still an example of a disjunction in which only one disjunct is weakly epistemically possible (i.e. only one that I don’t know to be false with certainty).  My existence is consistent with materialism, even if it is not consistent with every form of materialism.  If I knew with certainty that some metaphysical view entails that I do not exist, then I would know with certainty that such a metaphysical view is wrong.  It is not weakly epistemically possible for me at least that “it is not the case that I exist.”  I have at least as much confidence in my own existence as I do that all bachelors are unmarried.

No, I’m saying that while “Pr(R|N&E&SE) is inscrutable” entails that one could believe it is possible that “Pr(R|N&E&SE) is high” that person would not be warranted in believing it precisely because “Pr(R|N&E&SE) is inscrutable.”

Even if true (and I suspect it isn’t; some have countered the argument by saying e.g. N&E doesn’t entail SE), you have still avoided my question.  How did I try to justify 2.5? By arguing that “Pr(R|N&E&SE) is low” is true. If the justification for “Pr(R|N&E&SE) is low” works, then 2.5 is justified. Don’t you agree?

If (1) is justified then (2) is justified.  However, I believe “Pr(R|N&E&SE) is low” is what is justified, not (1).  Still, the argument doesn’t depend on which disjunct is justified.

What do you consider to be the main point?

You seem to have forgotten that “Pr(R|N&E&SE) is low” was my justification for 2.5.  It is not the case that 2.6 omits “Pr(R|N&E&SE) is high” because it is not strongly epistemically possible.  If one accepts that “Pr(R|N&E&SE) is inscrutable” is true, then “Pr(R|N&E&SE) is high” is consistent with the beliefs one is properly justified in believing, but the person would not have warrant for “Pr(R|N&E&SE) is high.”  That said, I think Pr(R|N&E&SE) really is low and that Pr(R|N&E&SE) is not strongly epistemically possible (for me at least).

Well, you’d have to modify the other premises to get 2.6’, but I do believe that 2.6’ is warranted because I believe “Pr(R|N&E) is low” is warranted.

Perhaps I was being overly charitable in hesitating to believe your answer might not have been no, but I hesitated because that response is so irrational.  “Irrational” is a strong word, but if a person believes that an argument is both valid and has true premises, he cannot deny the conclusion except on pain of irrationality.  It is logically impossible for a valid argument to have all its premises true and yet have its conclusion false (remember, in logic a valid argument is one where it is impossible for the premises to be true and the conclusion to be untrue, and therefore a valid argument is one where all true premises guarantee the truth of the conclusion).  A valid argument with its premises all true is by definition a sound argument.  Believing that a sound argument has a false conclusion is on par with believing there is a married bachelor.

No, it’s just that your response was so irrational I could hardly believe that you were disagreeing with me on this point.  Not many would claim that one can rationally deny the conclusion of an argument that one knows is sound (deductively valid + true premises).  One might as well say it’s rational to believe in married bachelors.

Next I’ll discuss the claim, “at least one of the disjuncts is true means that all the disjuncts are at least weakly epistemically possible.”  This is claim is manifestly false, since “there is a married bachelor or it is not the case that there is a married bachelor” is a true disjunction where only one of the disjunctions is epistemically possible.

I agree it would be self-contradictory, but that doesn’t make it literally meaningless.  If it were literally meaningless it wouldn’t be self-contradictory (because it would have no meaning that would contradict with itself).  Besides, you yourself believe that one can rationally deny the conclusion of a sound argument, even though a sound argument having a false conclusion is just as self-contradictory as a married bachelor.  Also, a truly meaningless statement cannot be true or false, whereas “a married bachelor exists” is clearly a false statement, and thus qualifies as a proposition.  Indeed, for any proposition p, “p and not-p” is itself a proposition, albeit one that cannot possibly be true.

You could amend your claim by saying, “at least one of the disjuncts is true means that all the disjuncts are at least weakly epistemically possible if none of the disjuncts is logically impossible,” but that would be a different claim, and even that one isn’t true.

I don’t think that even Daniel Dennett would say that I don’t exist in the relevant sense.  Suppose someone murdered me, is brought to trial, and Daniel Dennett is part of the jury.  The murderer claims he did not kill me because I did not exist.  Would Daniel Dennet buy his argument?  Obviously not.  You twisted the “I exist” proposition into something other than what I intended it to mean, because it doesn’t in itself imply the falsity of eliminativism.

I did partly clarify by noting that the type of existence I have in mind is such that if x has any experiences or mental states at all (such as believing that one exists) then x exists.  Again, “I exist” isn’t assuming any metaphysical view of existence in particular, so we can use the ordinary definition of “exist” as e.g. “to have real being whether material or spiritual” (from Merriam-Webster).  Thus, “I exist” is an incorrigible belief; it’s impossible to both believe it and be mistaken about it.  Knowing this, I also know “I exist” is true with absolute certainty.  Consequently, “I exist or it is not the case that I exist” is a counterexample to the claim “at least one of the disjuncts is true means that all the disjuncts are at least weakly epistemically possible if none of the disjuncts is logically impossible.”  (“I exist” is incorrigible but it’s logically possible for it to be false; my existence is certainly not logically necessary.)

You’ve again twisted my words to mean something other than what I intend them to mean.  “I am experiencing qualia” is not presupposing that Dennett’s view is false here, and is in fact consistent with it.  If Dennett witnessed a murder and was asked to be an eyewitness, I doubt he’d deny that he had ever seen the murder on the basis of his not having any qualia (since having no qualia entails that the person isn’t an eyewitness to anything).

If you feel I have insulted you I apologize; that was not my intention. Again, when I said one of your responses was irrational (the response that one can rationally avoid a conclusion of an argument that one knows to be sound), I was speaking of the response qua response. I was attacking the position, not the person. No insult was meant.

No.

I kind of explained this in my previous post in the quote. 'If I lost my warrant for “Pr(R|N&E&SE) is low” odds are “Pr(R|N&E&SE) is inscrutable” would be true for me, in which case both 2.5 and 2.6 would still be warranted.' If my warrant for "Pr(R|N&E&SE) is low" were defeated, would I be warranted in accepting 2.5? The short answer is, it depends. It depends whether I would have warrant for the other disjunct, but I think I probably would have warrant for it if I didn't have warrant for the other disjunct.  Pr(R|N&E&SE) is low or at best inscrutable, though my money is certainly on the former.

Although my justification for 2.5 is that “Pr(R|N&E&SE) is low,” to defeat the premise one would have to defeat not just “Pr(R|N&E&SE) is low” but also avoid affirming that Pr(R|N&E&SE) is inscrutable.  If for example one were to attack 2.5 on the grounds that we can’t possibly know what Pr(R|N&E&SE) is, it might attack my justification for 2.5 but would also (paradoxically) affirm the truth of 2.5.  To defeat the probability thesis the naturalist must avoid affirming either disjunct, which is one of the reasons why EAAN is so difficult to successfully refute.

Of course, if one proved that Pr(R|N&E&SE) is high, this would defeat the premise.

Not as such; 2.5 just says "Pr(R|N&E&SE) is low or inscrutable."

Assuming I knew that both X and Y cannot obtain, yes.

That's not quite accurate. Suppose for example I knew that P was true.

A1-1: P or Q <--true because at least one disjunct is true (namely, P)

A2-1: P or Q or R <-- true because at least one disjunct is true (namely, P)

That "A1-1 or A2-1 must be false" thus appears to be mistaken.  Also, if I know that P is true than both A1-1 and A2-1 are warranted for me.