Why is it that that the Sith cannot come back in ghost form (spririt) and Jedi Can? I know that Jedi have mastered the more difficult path and reached some karmic enlightenment, yielding the next step of a spirit of greater power that is not bound by the limitations of an earthly body. I assume that since take the darker path, the quicker path to power that they never reach the enlightenment required, though physically, it seems, they have more power in their physical bodies. So this is why Darth Maul, Darth Siddious or Tyrannus can not come back in some form in the movies. Correct?