The Force: A Detailed Explanation
Part 6 - The Dark and Light Side of the Force
The Lesser Force also has two aspects: positive and negative, widely known as "the Light Side of the Force" and "the Dark Side of the Force."
In the Light Side reside affection, compassion, and tranquility or peace. In the Dark Side are the counter of all these: hatred, anger, and fear.
The Jedi seeks to balance the Force. When the emotions of the Light Side evoke and govern those of the Dark, there is symbiosis and balance. For example, when anger out of compassion and protection for the innocent, anger is utilized symbiotically, and inner balance is attained. Jedi thus strive to purge their motivations of all Dark Side emotions.
When the Dark Side motivates - when anger, hatred, or fear evoke the thoughts, feelings, and actions of the Living Force - the emotions of the Light Side is smothered. One becomes dominated and consumed by the power of the Dark Side.