Each of the class stories started from a single core idea; the Knight, for example, came from the idea that the Knight would have to face the full might of the dark side alone, while the Consular was seen as a Jedi facing threats that couldn’t simply be seen and fought. It’s an interesting look at the ideas that ultimately turned into the stories you can now play in the game, and a neat retrospective now that all classes are firmly entrenched in a struggle against the Eternal Empire.
Source: Official Star Wars site