Tiriol wrote:First of all, the original Dark Jedi have evolved into the Sith, ideologically speaking, and their whole ideology is centered on the destruction of the Jedi, which is more than a mere schism. So long as there are Jedi and there are Sith, the Sith will try to subvert and destroy the Jedi invidually and as a whole.
Add that the Jedi wholeheartedly return those sentiments, and the problem is squared and cubed.
The dark side may not necessarily corrupt physically (although there are clear examples of this happening, King Ommin of Onderon being the most notable one, and arguably Palpatine himself), but it has tremendous psychological effect and has a disturbing tendency to cause sociopathic and psychopathic tendencies among those who use the dark side regularly. And since the dark side feeds on sapients' aggression, fear and anger, it becomes a moot point in trying to curb those tendencies in Dark Jedi students. The Force adepts who teach the dark side to their students actually urge them to use those feelings in order to become more powerful.
This might be an overgeneralisation; some dark Jedi we see are highly erratic and dysfunctional in their behaviour, and certainly exhibit traits that would be considered psychopathic (poor impulse control, heightened need for stimulation, and so on), but other users of the Dark Side, particularly those belonging to the highly disciplined Sithian traditions, display eminent self-control (easily on par with Jedi, beyond in some cases). In the case of the Banite Sith and their derivatives, they use their "negative" emotions as "fuel" for their abilities while overall suppressing them (a sort of sublimation mechanism, to some extent). They are not so much sociopathic as thoroughly pragmatic and amoral in the pursuit of their long-term goals.
The dark side also enhances the effects of anger, rage, hatred and wrath on its users to the point that even if they don't MEAN to cross the line, they will (Ulic Qel-Droma slaying his own brother is a fine example of this).
Generally, I would agree; even Palpatine, who at his height considered himself mostly beyond emotion, fell prey to this at times (nevermind that this is due to the power of shitty KJA writing . . .). Qel-Droma and Kun were, however, under the influence of various Sith magic and drugs at that time that had adverse effects on their sanity also, so they may not be the best examples.
All in all, any reconcilation between the Sith and the Jedi (or the Jedi and the Dark Jedi) is very unlikely, since it usually means either one converting to the other's point of view; the schism has happened so long ago over so fundamental differences that it cannot be repaired in any meaningful way; and actually actively teaching the dark side to students is tantamount of encouraging them to dwelling on their own frusfrations, aggressions and sociopathic tendencies and enhancing them. There is a reason why those Jedi who use the dark side often or who dismiss the Jedi philosophy concerning it have a bad habit of falling to the dark side (Darth Malak; Darth Caedus; and arguably Quinlan Vos to some extent).
That said, there has been one prominent attempt at reconciliation, namely the apostate Jedi Vergere's influence on Luke Skywalker's reformed Jedi Order in the late NJO Era. Her teachings considered adopting Dark Side methodology in pursuit of Light Side aims, something that has also been proposed by various Sithian or pseudo-Sithian Jedi schismatics in the past (aforementioned Qel-Droma and Vos, among others). The approach as such was not new,
per se, but this was the only instance I am aware of in which it gained any broader Jedi support. Of course, this theology was rejected as corrupt and misguided within a decade, as had been the original Potentium heresy in the waning days of the Old Republic.