William Camden wrote:aokoye wrote:leosmith wrote:1) Adequate mental health. In the past I left this out, but I’m attempting to include everything this time. I’m not saying someone needs to have above average intelligence, or that they must be free of mental illness; we have seen many examples of these not stopping someone from learning languages. I’m merely stating that there are some mental conditions, such as a coma, that would make it impossible.
You are conflating mental health conditions with neurological conditions which doesn't make much sense. Talking about learning disabilities like dyslexia and other processing disorders would be doing the same thing (and people with processing disorders can and do learn foreign languages). I do think that being able to manage one's mental health conditions plays a part in how efficient they would otherwise learn an L2, but that doesn't seem to be what you're saying.
Lee Harvey Oswald may have been dyslexic to some degree, although his difficulties with writing may also have reflected a patchy and frequently disrupted education. (He seems to have liked reading, however, so is unlikely to have been a severe dyslexic.) Whatever processing difficulty he had did not stop him learning to speak Russian although I don't know how well he could write in it.
I just want to point out that I'm by no means saying that having dyslexia, or any number of other processing disorders, makes it impossible to learn a second language. Will dyslexia make writing and/or reading harder? Probably, but that by no means is to say that it would be impossible. I know at least one very successful doctor who has dyslexia. Given she was able to get her doctorate I would assume that learning a second language would be something she could do if she so desired (and had the time which isn't a thing she has).
All I was pointing out was that what Leosmith had called mental health issues weren't actually mental health issues at all.