Does the Force use the Jedi, or the Jedi use the Force?

To use the Force, one must be at harmony with it. Only when calm, at peace, can one act with assurance of control. When one is at harmony with the universe, one acts as one must to maintain harmony. The will and the Force are one; the actor and the acted upon, the same. There is no contradiction: there is unity. That is the path of Light.

There is another - the path of Darkness. The universe is an angry morass of power. To release that power, one must harness one's basest emotions: hate, anger, fear, aggression. By releasing one's own anger, one releases the anger of eternity. Only when filled with hate, can one perform the most hateful of acts. The will and the Force are one.

That is the choice of the Jedi: serenity or hatred; peace or anger; freedom or tyranny; learning or power; the Light or the Darkness.

Because the use of the Force and the way the Force uses its user are one, the choice is inescapable. A Jedi who starts down the path of the Dark Side will forever be dominated by it. That is why the Jedi must follow a strict code.