George Lucas

"When Star Wars became a hit and I had a chance to make the other movies, I had to figure out a way to bring Ben back, but a lot of the issues he had to deal with were carried by Yoda. In a sense, I combined Yoda with the spirit of Ben. I wanted Ben to have some kind of influence, but I didn't want it to be a direct influence where he could help Luke. So Ben has managed to keep his identity after he became one with the Force. One of the things he was doing on Tatooine besides watching over Luke was learning how to keep his identity after he became part of the Force."
- George Lucas
Star Wars: The Annotated Screenplays

"One of the things that will never get explained in the films is how Ben was able to retain his identity, because it happened somewhere between the third and fourth movies. I set up that this is a discipline that he learned from Yoda; Yoda told him how to do that."
- George Lucas
1997
Star Wars: The Annotated Screenplays

I wanted Yoda to be the traditional kind of character you find in fairy tales and mythology. And that character is usually a frog or a wizened old man on the side of the road. The hero is going down the road and meets this poor and insignificant person. The goal or lesson is for the hero to learn to respect everybody and to pay attention to the poorest person because that's where the key to his success will be."
- George Lucas
Star Wars: The Annotated Screenplays

"I felt that one of the major issues in the third film is that Luke is finally on his own and has to fight Vader and the Emperor by himself. If you get a sense that Yoda or Ben is there to help him or to somehow influence him, it diminishes the power of the scene."
- George Lucas