I think Cadsuane, in the process of helping Rand and the Asha’man hold on to their humanity, will teach them also to hold on to their sanity. When Cadsuane was first mentioned in the series, it was said that she had done a lot of work with men who could channel, and all the men she had worked with had managed to hold their sanity longer than most.
wotmania says: I do not know necessarily that it is possible for Cadsuane to teach sanity. Just touching saidin lets the taint seep into a man who can channel. The men Cadsuane gentles tend to live longer than the average severed man, they do not hold off the taint longer.
No you cannot teach sanity, or hold of the taint, but now that the taint is gone, maybe she can help those who have succumbed to insanity.
It's pretty clear after having read book 9 that Cadsuane plans (I cannot say she will succeed as I don't know and quite frankly I don't want to,..yet) to teach Rand how to care again, yes in a way making him sane once more.
Unfortunatly the problem with using words such as sane/insane (sorry can't be bothered to delve into the recesses of my mind right now) is that they are subject to interpretaion, as are all words. Anyway back to my point(s).
I don't see Rand as being insane, he has/is losing his humanity but not his sanity. Rand is in a hideous situation which we are all hopefully aware of and is dealing with it by shutting himself off from as much of the world as he can, I believe that this is done as he would become insane if he were to allow himself to fully 'feel' the world around him, this is a process of de-humanisation. One of Rands ladies mentions that 'if he were stone before he was steel now' - WH.
And back to the original thread of my thought.
As Cadsuane has herself said (WH don't have books at hand) she will 'need to be there at the end to make him human again' - sorry bad paraphrasing.
sorry poorly written point.
CONCISE VERSION
Rand = Closing himself off from as much of the world as will let him, becoming harder - Cancerians should understand this. Not insane, if he were he would be far more irrational than he his.
Cadsuane = Wants to make him cry, to feel, to regret, to forgive etc.
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Cadsuane