The Force is a concept developed by George Lucas for his Star Wars films. In the Star Wars world, it exists in all living things and some individuals prove more adept at either perceiving it or wielding it. It is split into a dark and a light side. Giving way to emotions, particularly to fear, anger, and despair, makes a person susceptible to the dark side. Rigid control of emotion, and a sense of detachment from the world and worldly possessions, very much like that advocated in Buddhism, makes a person a better vehicle for the light side.
Lucas’ concept of the Force focuses on the idea that it is not good or evil. Rather, how someone uses it determines how it will change him or her personally, and how it will determine his or her destiny. For the Jedi order, the goal in using the Force is to allow it to flow through one freely, not giving into use of it in anger or hatred. People who use the dark side, called Sith lords, manipulate it for their own purposes. The Sith see it as a tool, while the Jedi view it as “the way.”
An analogy can be made between the light and dark side of the Force and the differing ideas of Christian religion and magic-based religions as explained by Joseph Campbell. In Christianity, a person prays for what he or she wishes, as a subject of God, who is not under your control. In magic, people attempt to manipulate gods or the universe to do what they want. Like this, Jedi are comparable to the idea of Christianity, receiving, while Sith are comparable to magic-based beliefs by taking.
Sith and Jedi must surrender to something in order to manipulate the Force. For the Jedi, surrender is to the Force only. The Sith, on the other hand, surrender to emotions of anger, hate and fear as this makes them more powerful in the dark side. A person surrendering to his or her emotions is likely to be "seduced by the dark side." The seduction seems more centered on seduction of negative emotions rather than the Force itself.
In Star Wars: The Phantom Menace, Lucas expands on his idea of the Force by suggesting that all people, and all things, have special microorganisms present in them, called midi-chlorians. A higher midi-chlorian count, tested by a simple blood test, gives the ability to wield the Force. In Episode One, Jedi Master, Qui-Gon Jinn tests Anakin’s blood and finds that he has a higher number of midi-chlorians than even Yoda. This knowledge persuades Qui-Gon to train Anakin as a Jedi, even though Anakin is technically too old to begin training.
Mention of midi-chlorians is not made in the first Star Wars trilogy, which actually covers a later time period in the Star Wars world. It is suggested in episodes four through six that the ability to wield the Force may be in part genetic. Both Luke and Leia inherit their ability from their father Anakin.
The Force can be used in numerous ways and certain types of uses are considered unconscionable by the Jedi order. For example, killing with it in any other means but to protect or defend others or one’s self is a path to the dark side. In fact, when Luke must face his father at the end of The Return of the Jedi, his goal is not to kill his father, but to prevail upon his father’s lingering sense of good, long buried by many evil deeds. The Emperor, witnessing this battle, urges Luke to seize his anger and kill his father, which would effectively turn Luke into a Sith.
Jedis tend to use the Force to defend and protect, to move objects with their minds, to read minds, to sense the future, and to influence the weak-minded. Jedis can also use it to live eternally. Siths use it, especially dark lightning, to kill, maim, harm, and destroy. They can employ telekinesis, mind reading and mind influence like Jedis, but they are a chaotic order that will easily pick each other off in power struggles.