Forgive me if this has been already talked about, but I was wondering when Luke goes to see Yoda in Episode V and Yoda begins to go on about how he could not train the boy, was Yoda at that point ready to concede victory to Vader and Palpatine? Or was he baiting Luke? Is it possible that he would not have trained Luke for fear of his following the same path as his father? Did he have a backup plan if Luke wasn't suitable? Or was he residing himself to the fact the galaxy was lost? To me he seems very unwilling to train Luke, but does it because he has no other choice. Had Ben not been there to argue for Luke, I don't think Yoda would have trained him.