An understanding of the Force is essential to the Jedi. The following text is taken from the Star Wars Wiki, hence being available under the GNU Free Documentation License.
The Force is a mystical power that is the object of the Jedi and Sith monastic orders.
The definition of the Force
The Force is described by Obi-Wan Kenobi as "an energy field created by all living things. It surrounds us, penetrates us, and binds the galaxy together." The Force is life, and life is the Force. It can only be harnessed by a minority of beings described as "Force sensitive," who have a high count of internal micro-organisms called midi-chlorians. The more midi-chlorians a body contains, the greater the person's Force ability. Force-adepts are able to tap into the Force to perform acts of great skill and agility.
Sources
Although fictional, the Force does contain many similarities to existing philosophical and religious principles. Many have related it to the concepts of Qi (also "chi" or "ki") (China and Japan), Prana (India), Mana (Polynesia) and other similar traditions focused around the idea of a spiritual energy that exist within the universe. Likewise can parallels in Dr. Wilhelm Reich's "Orgone" theories of the 1930s be seen. With Taoism, the primary focus for Star Wars originates in the idea of Yin and Yang—the two diametrically opposed Forces of the universe. Everything from good and evil (as metaphysical concepts) to hot and cold temperatures are considered as being part of this, and it is from here we see the most prominent comparison to the Light and Dark Sides of the Force in Star Wars. But, it must also be noted that it is even more similar to Taoist philosphy with less of a dichotomy and more of a necessary balance (seen in the philosphy of the balancing of the Force).
Some think of the Force as an entity that may be capable of intelligent thought, almost as if it were a sort of god. Anakin Skywalker was conceived by the messengers of life, the midi-chlorians, and other events have occurred which some say point towards an understanding of the Force as sentient.
The sides of the Force
Orthodox Jedi philosophy
The Jedi and others refer to two sides of the Force, a dark side and a light side. This echoes the concept of "Yin Yang" in Eastern philosophy, but is not a straight translation, as the emotional Dark Side is denoted as a force of evil by the Jedi. The Dark Side is not made up of specific "parts" or "abilities" of the Force: the Dark and Light sides of the Force exist inside of the life form which uses it, made from their emotions. George Lucas compared the Light and Dark sides to the processes of symbiosis and cancer. A follower of the Light Side tries to live in harmony with those around him. Mutual trust, respect, and the ability to form alliances give the Jedi their distinct advantage over the Sith. In contrast, a follower of the Dark Side is only out for themselves. To strike down a living creature with the Force out of anger, fear or other emotion is of the Dark Side. To refrain and clear one's self of these emotions is of the Light Side. Use of the Dark Side of the Force is distinctly frowned upon within the Jedi Order, and is strictly considered the domain of the Sith. The Force plays a major part in the Jedi use of a lightsaber in that their heightened awareness keeps them from accidentally injuring themselves while in combat using the weapon. Similarly, the Force allows a Jedi to use his/her lightsaber to deflect incoming blaster bolts. The Force also comes into play during the construction of a lightsaber, either in assembling its intricate innards, or the initial charging of the power cell.
Jedi are keen to keep the Force in balance. They attempt to achieve this by destroying the Sith and denying the Dark Side, as the Dark Side is corruption. This involves the purging of negative emotions such as aggression, anger, and hatred, since they can easily bring on acceptance of the Dark Side. In contrast, positive emotions such as love, compassion, and courage nurture the Light Side of the Force. The Jedi Code compares such feelings and provides insight into the ethical use of the Force.
Sith philosophy
The Dark Side of the Force is innately tied to the distinctly negative ethical paradigm of the Sith. It comes from the hate, vengeance, and malice in all living things. In the Star Wars movies, the practitioners of the Dark Side are Darth Sidious and his successive apprentices Darth Maul, Darth Tyranus, and Darth Vader.
The Jedi believe that emotions such as fear, uncertainty, doubt, anger, suffering, and attachment are "inevitably" self destructive, and lead to the Dark Side. The Sith philosophy, on the other hand, is to use such emotions to fuel one's own will to power, ego, and selfishness. Sith philosophy sees no need to apologize or rationalize the destruction and conflict to which it leads; such concerns arise from moral frameworks more akin to the Jedi Code.
The negative emotions increase the strength and abilities of a Dark Side practitioner. As a result, the Dark Side of the Force is extremely addictive: every time one calls on its power, one becomes more and more attached to it. Darth Vader desired to use this to his advantage during his time trying to turn his son, Luke Skywalker, to the Dark Side. If he could convince the young Jedi hopeful to call on the Dark Side enough times, the boy would find it more difficult to resist in the future. The Dark Side is not only mentally corruptive, but also physically corruptive: over time, the raw power wastes away the body of a Dark Side adept (see Palpatine).
Overall, Dark Side relationships and organizations are inherently unstable. For instance, the pupil-master relationship of the Jedi is perverted under the Sith, as both the apprentice and the master naturally plot against one other, and one will eventually kill the other. Every time a Dark Side force has risen in the Galaxy, it has collapsed from within due to its own unstable nature. The Empire is no exception.
The Sith Lord Darth Bane considered the Force to be finite, and thus best restricted (ideally) to the use of the Sith Lord. He eliminated the practice of having vast numbers of Sith at the same time and concentrated the Dark Side of the Force into two individuals: a Sith Master and apprentice. This tradition, or "rule of two," is still in practice with the current Sith Order, which underwent a small reformation by Dark Lady Lumiya after the deaths of Darth Vader and Emperor Palpatine at Endor.
Potentium and unitary views of the Force
The Potentium view of the Force, considered heresy by Old Republic Jedi, holds that the Force, and the galaxy in general, were given a master plan which was inherently good, and that there was no dark or light side to the Force. This view gained greater acceptance under the New Republic, mostly due to the influence of Vergere, a surviving Jedi from the days of Old Republic.
Emperor Palpatine (Darth Sidious) says that there is only one Force: the only difference worthy of note is that the Sith see the Force as a means to an end; the Jedi as an end in itself.
This is echoed by what Vergere teaches Jacen Solo in the New Jedi Order novel Traitor (part of the Expanded Universe of Star Wars). She tells him that there is no Light Side or Dark Side of the Force—only the Unifying Force. Vergere also tells him that the Force is everything, and everything is the Force. The Force also does not have sides and never takes sides. Later, it is revealed that the living planet Zonama Sekot, supports the Potentium theory of the Force.
Philosophical view
The Force is the pure energy of awareness and consciousness itself. It links all sentient and non-sentient things, all space, and all time. Thus, if you are aware of your contact with the Force, you are potentially aware of all things, places, persons and even all times past, present and future.
The Force touches all things, and a Jedi is never out of touch with the Force. That is why a Jedi can move objects without physically touching them. The Force is in your heart. Thus a Jedi who knows the Force can know the feelings you hide inside. A Jedi can see the myriad possibilities of the future because he can see the Force, which permeates not only the present, but the past and future(s) as well.
The galaxy, the universe, and everything exist within the Force, and that Force originates from an ultimate and para-cosmic Will.
The Greater and Lesser Force
The Force exists in the universe by assuming two aspects: The Greater "Cosmic" Force, which is and expression of the Ultimate Will and the Lesser "Living" Force, an intrinsically distinct emanation from the Greater Force, which constitutes the individual wills.
The Greater and the Lesser Force are inherently linked, and may thus interact with and affect one another. Their interaction leaves a "footprint" trace in the form of mysterious living particles in the blood known as Midi-chlorians. These Midi-chlorian traces also serve to facilitate and enhance further communication between the Greater and Lesser Force.
In ancient times it was held by many that Midi-chlorians were not distinct entitites, but rays of the Greater Force itself. This view is still held by many Jedi.
There are infinite Living Forces, each with unique and intrinsic identity, emotional temper, cognitive bent, and will. Each individual Living Force can interface with and/or influence any other individual Living Force, sentient or not, through a "bridge" established in the Cosmic Force.
A Jedi can thus understand and influence the people and objects around him or her in apparently mystical ways.
Destiny and the Force
The Cosmic Force witnesses the thoughts and feelings of the Living Forces, and gives them the ability to act on their own free will.
The thoughts and actions of the Living Force shape his destiny, which the Cosmic Force records and administers.
One can choose to embrace his own destiny, or can attempt to defy it. The Jedi's sensitivity and courage allows him to understand his own destiny and embrace it as the will of the Greater Force.
Thus, the Jedi opens a channel linking the Lesser and Greater forces together more strongly. The power of the Greater Force can now flow into the Jedi, who then works with amazing power in the world around him.
The Dark and Light Side
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. The Jedi seeks to use these emotions to fuel their ability to help others. In the Dark Side are the counter of all these: hatred, anger, and fear. The Dark Jedi seeks to use these emotions to enhance their own power.
The abilities of a Jedi
Manifestations of Force-skills include telepathy, psychokinesis, enhanced physical and metaphysical perception as well as the abilities to bend the will of the weak-minded and improve one's own physical ability. The Force can also be used to allow an adept's body to be guided by the Force itself: such action enabled Luke Skywalker to launch a proton torpedo into an extremely difficult target on the Death Star in the Battle of Yavin. Through this ability one can cease to react to his or her surroundings and predict the future, such as the next blow in a duel.
In addition to the above powers, force users are also capable of attacks through The Force by means of force-lightning and force-choke, among others. Use of this ability murderously is of the Sith cult. As a contrast, Jedi prefer abilities such as force heal and force shield. After death, Jedi can achieve near-immortality by existing as a force ghost.1 This ability was discovered by Jedi Knight Qui-Gonn Jinn.
Some Jedi and Sith have learned the skill of transferring one's spirit to another body. Palpatine used this in order to preserve himself with his failing body, and later, Callista transferred herself to the body of a dying friend so that she could stay alive. Unfortunately, in the process of doing this, she lost her ability to touch the Force.
Disturbances in the Force
When Alderaan was destroyed, Obi-Wan Kenobi sensed "a great disturbance in the Force, as if millions of souls cried out in terror and were suddenly silenced.…" The Force exists in all life, and when great amounts of life pass away, a disturbance is created, running through the Force like a scream which Force-adepts can hear. In the same way a "Hole" in the force was created at the battle of Malachor V during the Mandalorian wars when the Mass Shadow Generator was unleashed.
Sometimes, other things are defined as disturbances. Life creates small disturbances, and Force-adepts even more so. Dark Side users create strong, evil feeling disturbances.
May the Force be with you …
The Force is associated with a phrase used by some characters in (and fans of) the films: "May the Force be with you," meaning something like "Good luck", although usually only Jedi and other believers in the Force use the expression. Han Solo, who expresses his doubt about the Force in A New Hope, eventually uses this expression to wish Luke good luck. George Lucas used the Christian phrase "May the Lord be with you and with your spirit," as the model for it.
The expression has found its way into popular culture as a result of the popularity of the films.
Some might believe that, as the Force exists between all living things in any case, the phrase reflects a misunderstanding of its nature. In fact, the phrase implies a wish that the power of the Force is working alongside you, in order that your goals are more effectively accomplished. Jedi Master Obi-Wan Kenobi always used a different form that expressed a reminder rather than a wish: "The Force will be with you, always," stating that his apprentice would succeed, as he working alongside the power of the Force.
The Living Force
The Living Force is present in most living beings. The Jedi have the ability to sense the Living Force in life-forms. Sick or dying organisms have little Living Force, while healthy ones usually have the quantity of their midi-chlorian count. The connection to the Living Force apparently also allow Jedi Masters to retain their identity when they become one with the Force. The only known species without the Living Force are the extragalactic Yuuzhan Vong. They exist without the Force and it has no effect them. The Force however can be used to manipulate their surroundings. The Yuuzhan Vong once existed with it but were stripped of the Force by the Yuuzhan'tar, a living planet which was the parent of Zonama Sekot. The Yuuzhan Vong were stripped of the Force, after they used their biotechnology to conquer and enslave other civilizations after an encounter with a technologically advanced species which attacked them. Yuuzhan'tar was later destroyed by the Yuuzhan Vong. As a result, the Yuuzhan Vong deny the existence of the Force and in its place, they have a pantheon of gods.








