Yoda: Yes, a Jedi’s strength flows from the Force. But beware of the dark side. Anger, fear, aggression; the dark side of the Force are they. Easily they flow, quick to join you in a fight. If once you start down the dark path, forever will it dominate your destiny, consume you it will, as it did Obi-Wan’s apprentice.
Luke: Vader… Is the dark side stronger?
Yoda: No, no, no. Quicker, easier, more seductive.
Luke: But how am I to know the good side from the bad?
Yoda: You will know… when you are calm, at peace, passive. A Jedi uses the Force for knowledge and defense, never for attack.
[Luke’s ship sinks into the swamp.]
Luke Skywalker: We’ll never get it out now!
Master Yoda: So certain are you. Always with you it cannot be done. Hear you nothing that I say.
Luke Skywalker: Master, moving stones around is one thing. This is totally different.
Master Yoda: No! No different. Only different in your mind. You must unlearn what you have learned.
Luke Skywalker: Alright, I’ll give it a try.
Master Yoda: No. Try not. Do or do not. There is no try.
[Luke attempts to pull the ship out, but only with minimal success.]
Luke Skywalker: [panting]I can’t. It’s too big.
Master Yoda: Size matters not. Look at me. Judge me by my size, do you? Hmm? And well you should not. For my ally is the Force. And a powerful ally it is. Life creates it. Makes it grow. Its energy surrounds us, and binds us. Luminous beings are we, not this crude matter. You must feel the Force around you. Here between you, me, the tree, the rock, everywhere. Yes, even between the land and the ship.
Luke Skywalker: You want the impossible.
[Yoda raises Luke’s ship from the swamp.]
Luke Skywalker: I don’t…I don’t believe it!
Master Yoda: That is why you fail.