So I'm driving home, working out plot lines in my head, and I'm suddenly struck by the odd dialogue in a crucial scene in ESB. Given that it's SW, I guess I shouldn't be phased by odd dialogue, but that's not really my point.
Anyway, in ESB when Palps calls Vader to discuss the Luke problem, Vader makes the plea,"If he could be turned, he could be a powerful ally." Turned is the word that is used consistently throughout the saga to describe one who has made the journey to the Dark Side. And turned ain't a good thing. Like milk that has turned, a person who has turned is corrupted, rotten, and no good anymore.
Now given that Vader and Palpatine have turned to the Dark Side, do they view themselves as corrupted? Wouldn't it be more likely that Palps especially would say,"If he could be enlightened..."?