A lot of us are probably aware by now that in the screenplay for Revenge of the Sith (and in the novelisation and comic book adaptation), the spirit of Qui-Gon Jinn informs Yoda that he learned the secret of preserving his consciousness in the Force from a Shaman of the Whills, and also adds that this is something that those consumed by the dark side can never learn. It is assumed that Qui-Gon then goes on to teach this ability to both Yoda and Obi-Wan in the years between ROTS and ANH. But things become much more problematic when one takes the Expanded Universe into account, as a great many EU stories have shown other Jedi, sometimes long before Qui-Gon, disappearing into the Force upon the death of their physical body (Arca Jeth and Ulic Qel-Droma in Tales of the Jedi, for example). Not only that, but the EU has also shown how a great many Sith have appeared as spirits in the physical universe after their bodies' demise, such as Freedon Nadd and Exar Kun (And in Nadd's case, his ghost was able to appear anywhere in the galaxy). So much for dark siders being unable to cheat death, eh? There's also the Jedi ghost that haunts the library on Nespiss VIII in the Galaxy of Fear book Ghost of the Jedi. And during her funeral, the body of Mara Jade Skywalker vanishes into the Force, and she later comes back as a Force ghost, despite the fact she never received any special incite from any shaman of the Whills! How do we go about resolving these conundrums?