This has been nagging at me for a week, and so I'll go ahead and write it. I was so charmed by your mention of The Boxer, that I let something else you wrote slide: You can't exclude the SOTU as evidence of whether Biden has dementia. A single counter-example is sufficient to prove a proposition false. If a person with dementia could not have given that SOTU, Biden does not have dementia. I've spent enough time around people with various degrees of dementia to believe that a person with dementia could not have given that speech as he did, drugs or no drugs. He was alert, he spoke with expression, indicating that he understood what he was saying, he reacted quickly to the heckling. As you say, that's my perception and our perceptions can differ, so we probably have to agree to disagree about that. But the SOTU can't be ruled out as evidence for whether he has dementia.
This has been nagging at me for a week, and so I'll go ahead and write it. I was so charmed by your mention of The Boxer, that I let something else you wrote slide: You can't exclude the SOTU as evidence of whether Biden has dementia. A single counter-example is sufficient to prove a proposition false. If a person with dementia could not have given that SOTU, Biden does not have dementia. I've spent enough time around people with various degrees of dementia to believe that a person with dementia could not have given that speech as he did, drugs or no drugs. He was alert, he spoke with expression, indicating that he understood what he was saying, he reacted quickly to the heckling. As you say, that's my perception and our perceptions can differ, so we probably have to agree to disagree about that. But the SOTU can't be ruled out as evidence for whether he has dementia.