You are arguing by definition (little can be learned with way), and throwing in infinite certainty. I doubt an anosognosic believes that it's impossible for them to be paralyzed more than I believe that 2+2=4, or that there is no God. Maybe that belief isn't even that strong, the only problem with it being that it won't go away in the face of counterevidence.
I doubt an anosognosic believes that it's impossible for them to be paralyzed more than I believe that 2+2=4, or that there is no God.
I don't know if that's correct, actually.
Anosognosia seems to be a symptom of a catastrophic failure of the brain's ability to reconsider current beliefs in light of new evidence; these systems are apparently localized to the right hemisphere, which is why you won't find anosognosiacs with paralyzed right arms, only left.
If a god descended from the heavens and spoke to you, personally, declaring existence and providing my...
Followup to: The Strangest Thing An AI Could Tell You
Brain damage patients with anosognosia are incapable of considering, noticing, admitting, or realizing even after being argued with, that their left arm, left leg, or left side of the body, is paralyzed. Again I'll quote Yvain's summary:
A brief search didn't turn up a base-rate frequency in the population for left-arm paralysis with anosognosia, but let's say the base rate is 1 in 10,000,000 individuals (so around 670 individuals worldwide).
Supposing this to be the prior, what is your estimated probability that your left arm is currently paralyzed?
Added: This interests me because it seems to be a special case of the same general issue discussed in The Modesty Argument and Robin's reply Sleepy Fools - when pathological minds roughly similar to yours update based on fabricated evidence to conclude they are not pathological, under what circumstances can you update on different-seeming evidence to conclude that you are not pathological?