And, as his overall premise is "my existence is so unlikely under H that something else must be more likely"...
I think it's more accurate to say his premise is, "My existence is so unlikely under H that
anything else must be more likely." He told us all he needed was a "reasonable alternative." While he postures his immortality theory as that reasonable alternative, the point he made was that any reasonable alternative would do.
As I've previously discussed, this is the most common approach in fringe argumentation. The conventional theory or narrative is dismissed according to a particular standard of proof that argues the theory is unacceptably improbable. Some desired alternative theory or narrative is then put forward as one that must therefore hold (or at least be considered) no matter how improbable or unsupported it seems on its face. The claimant often argues it doesn't need substantial proof because its competitor was eliminated. "Once you have eliminated the impossible," says Sherlock Holmes, "whatever remains, however improbable, must be the truth." Not a rule of logic, and in fact Sir Arthur Conan Doyle was not the brightest bulb on the Christmas tree.
In this case -- as you go on to note -- Jabba's choice among the alternatives is unfortunate because it depends, probabilistically speaking, on the hypothesis Jabba dismissed. Not all Bayesian inferences go that way.
H is the materialist hypothesis, under which consciousness is an emergent property. Jabba wants to call it "OOFLAM," which is in fact the consequent to such a theory: we have at most one finite lifetime. But in order to reckon anything like P(E|H), where E is any event, H must embody some line of reasoning that leads to H. That explanatory power is exactly what is meant by P(E|H) -- how plausibly would materialism explain something if we suppose that the thing happened?
The proffered E helps us correct the problem. E is "I exist as a self-aware being." (Although we did get Jabba at least to concede that he can't pick a particular person.) We render P(E|OOFLAM) textually as "How plausible is it that I have a sense of self if we have at most only one finite life?" An obvious
non sequitur. The several consequents of materialism don't themselves have explanatory power. They don't provide an operative line of reasoning that allows us to reason quantitatively about P(E|OOFLAM). Hence OOFLAM is a red herring.
The scientific position is materialism. Specifically applied to human life, the scientific theory is that everything a human being is, including its self-awareness, is a product of the physical organism. A consequent of that is the limitation of that self-awareness to the term of the physical body, which we observe to be finite. Mortality follows from materialism. It's not a separate theory.
If H is materialism, then ~H is everything that isn't materialism. And it follows that not everything that isn't materialism leads to immortality. We can have an immaterial aspect to our being, somewhat independent of the organism, that may still not be immortal. It may, for example, cease to exist a few minutes after the physical organism, never to exist again.
I'm getting there, I promise.
So Jabba purports to compute P(H|E) -- if we correct his formulation as
jsfisher did -- as P(H|E) = P(E|H) * P(H) / P(E). That would be usable if suitable values for the terms could be found. (And if you could somehow avoid the Texas sharpshooter fallacy inherent to Jabba's E.) But because this is just a mathematical version of the typical fringe error, he's only half done. Having computed, as he thinks, a very low value for P(H|E), he thinks he can conclude by corollary that P(~H|E) must be very large. But ~H is not "immortality." ~H is just "not materialism." This could be why Jabba, years ago, begged to be allowed only to prove instead that materialism was false. He might have seen that that's all his false-dilemma formulation could ever have shown.
As I've previously noted, within ~H there may be
specific hypotheses whose consequent would be immortality. But because they would form only a proper subset of ~H, you can't reckon any one of their probabilities as anything except something less than P(~H|E) -- perhaps something drastically less.
If K, L, and M are each separate theories from ~H to explain self-awareness in the physical organism, then Jabba would still have to compute
P(K|E) = P(E|K) * P(K) / P(E)
P(L|E) = P(E|L) * P(L) / P(E)
P(M|E) = P(E|M) * P(M) / P(E)
He doesn't get to assume any of them are greater than P(H|E). Moreover, in this particular problem we observe that for all
x in {K, L, M}, P(
x|E) ≤ P(H|E). All theories leading to immortality must assume
at least the physical body that's observed in E, but that's all H requires. His math just doesn't work out.
Indeed, he refuses to put it into his summary much less attempt to address it.
It seems this is the new order of "I guess I just don't understand." Whatever he doesn't decide to address simply doesn't exist and doesn't affect what he states as his argument. By rights I should have included it as a fatal flaw in my summary. But I named only the fatal flaws that arose out of his latest manifesto, and Jabba has said he will limit his anointed critic to a serial examination of responses to his claims. It doesn't appear that the designated critic will be able to raise issues not strictly covered in Jabba's claim. Cross-examination only.
Obviously Jabba doesn't believe he can prevail without exerting disproportionate control over the debate. That's why venue-shopping is a big part of the fringe meta-argument strategy.
