Trailor

 You might have seen this symbol before, It's called the Yin-Yang symbol. It comes from Taoism,

 

The Yin is the dark swirl, and the Yang is the light one, and each side has a dot of the opposite color,
everyting contains the seed of its opposite.
Darth Vador has the seed of goodness, and Luke has the potential to follow his father to the dark side.
Like Luke and his father, Yin and Yang are not total opposites, they are relative to each other.
Something can be Yin or Yang
So while wheat that's growing is Yang, when it's being reaped, it's Yin.
An eggshell is Yang, the egg inside is Yin.
One can turn into the other or are two sides of the same coin.
The moon, is Yin, the Sun is Yang. 
The pitch is Yang, the catch is Yin.
The yang starts an action, and the Yin receives it.
Yin is the inside space of a cup; it wouldn't be a cup without it.
Yang is the cup.
Yin is the darker swirl, the female, but there is a white dot in it.
And Yang is the lighter, the male, but it has a black dot.
Taoism teaches that we need to learn from both Yin and Yang.
Like the force in Star Wars, the Tao has two sides.
Unlike religions with gods that are personal,
the higher power in Taoism is not.
Taoism teaches that we need to learn from both Yin and Yang.
Learning to use the Tao is what Taoism is all about,
and that's why you should know your Yin from your Yang.