In the Star Wars universe, the Jedi follow a strict set of rules which exemplify their ideals. This set of rules is known as the Jedi Code:

There is no emotion, there is peace.
There is no ignorance, there is knowledge.
There is no passion, there is serenity.
There is no chaos, there is harmony.
There is no death, there is the Force.

The code is based heavily on meditations on the Force by the Jedi Master Odan-Urr, a veteran of The Great Hyperspace War, who was killed by the fallen Jedi Exar Kun.