In the world of Star Wars, life often seems very cut-and-dry: there is a good side, and there is a bad side; there is darkness and there is light; everything is about dichotomous balance. But when you start digging deeper into the history of the Star Wars Universe, whether in the Expanded Universe/Legends imprint, or in the still-canonical parts of the universe, you begin to find things to challenge that accepted knowledge. You will find Sith who were noble people, living what could be a life of moderation, and you find Jedi who are willing to enslave or destroy entire races.
This is not an article about justifying the Sith, or trying to glorify something evil -- this is about picking apart the threads of the good guys, seeing where the Jedi start to unravel and reveal themselves as what they really are -- fallible, normal people, who have been given extraordinary abilities by the universe. When given absolute power, often the Jedi can remain aloof and objective, but sometimes even a Jedi can fall prey to a base instinct under the guise of honor and duty. These are only 15 of the most egregious of the many dark secrets hiding under the veneer of the Jedi Order. Brace yourself.
15 EXPERIMENTATION ON LIVING BEINGS
In the old days of the Jedi Order, at the time of the Second Great Schism, some Jedi realized that if you focused strongly enough on the Force, you could use it to later life itself. You could change the makeup of matter, you could; when they were denounced as heretics by the Jedi, they were named Dark Jedi and shunned.
The Dark Jedi came into conflict with the Jedi Order and raised genetically altered beasts, like the Leviathan, as well as zombified hordes of fallen warriors to fight the Jedi. After the Dark Jedi were finally defeated, they were expelled from Tython by the Jedi and launched into Wild Space, presumably to be killed or die in the transportation. Instead, the Dark Jedi found a new society -- the Sith.
14 THE PRISM
An obvious parallel to Guantánamo Bay, one of several great stains on America's national reputation, the Prism was built by the Jedi Order during the Hundred-Year Darkness. Hidden in the uncharted depths of Wild Space, the Prism ("the Ghost Prison," as it was known colloquially) was intended to imprison Sith during the Great Schisms; the prison was staffed entirely by hundreds of warden droids and supervised by one Jedi Master.
Surely that's the optimal situation for a prison -- giving one person complete authority over the fates of hundreds of criminals and then removing them from any meaningful interaction with any other sentient life form aside from their charges; surely that wouldn't lead to an abuse of authority. Eventually, the Prism was discovered by Darth Vader, who freed all the inmates -- and forced them to fight each other to the death for the privilege of serving as his own personal army.
13 DAEGEN LOK
Daegen Lok was one of the first of the ancient Je'daii Order to fully turn to the Dark Side of the Force. After a great military victory (in which he became a Queen's general and lover so that he could get close enough to assassinate her and end a war), Lok ventured into "The Chasm," a place similar to the Yoda's dark grotto on Dagobah. Presented with visions of a stranger wielding blades of fire, Lok became a Dark Jedi, and was exiled.
He met Xesh, the man who knew how to create Forcesabers, and the two of them escaped to build the blades. Eventually, Xesh turned on him, and the Je'daii reinstated him as a general, but the important part is their response initially -- faced with a warning about something that could (and did) cause a war, they chose to lock up a heretic. It's a Galileo-vs.-the-Pope look, and it's not a good one.
12 FORCE PERSUASION/THE JEDI MIND TRICK
In Star Wars, Obi-Wan Kenobi casually waves a hand outside Luke's landspeeder and reminds the stormtrooper at the Mos Eisley checkpoint that their droids were not the droids they were looking for. It's an iconic moment, and the scene's shorthand gets across the mysterious power of an old Jedi Knight, and gives the audience an idea of how he and an idiot moisture farmer might be able to fight the Empire. But it also removes any of the willpower that stormtrooper had.
The incident is more troubling when viewed in conjunction with the scene in Attack of the Clones in which Obi-Wan is offered "Death Sticks" (contractually-not-cigarettes), and tells the man he doesn't want them and that the man will go home and rethink his life. We have to assume that's what he did, and that Obi-Wan just pulled a serious Get Out on the guy to cure his smoking habit.
Many Star Wars tales of the Jedi feature them heading out on long trips through hyperspace and putting themselves into essentially suspended animation; using the power of the Force, they shut their body down to its bare minimum of functionality, eliminating the need to eat, and almost the need to breathe. It's a technique called morichro, and while it is widely practiced, it is rarely mastered, though famously by Yaddle. The real danger here is that morichro can be performed on someone else.
A Jedi, if they decide that they really need to (or, troublingly, want to), can shut down someone's bodily functions remotely, hitting the snooze button on anyone. Like many of the problems with the Jedi, the real trouble is the lack of accountability in this scenario -- it's the potential to be cursed in passing by a Jedi with the failure of your own body.
10 THE SECOND GREAT SCHISM
The Jedi Order has a history that goes back thousands of years, with the first real coalescence of the modern iteration occurring on the planet Tython about 40,000 years before the Battle of Yavin (everything in the Star Wars universe is dated by its relationship to the Battle of Yavin -- the New Republic creating its own calendar, perhaps). Like any religious order, it is marked by schisms -- rather than joining together for a Nicene Creed of the Jedi Order, it continues to split.
The Second Great Schism was the expulsion of Dark Jedi who were practicing alchemy, before a conflict called the Hundred-Year Darkness; the displaced Dark Jedi eventually landed on a lost planet called Korriban, inhabited by a native people who worshipped the newly arrived Jedi as gods. With the adulation of the Sith, the Dark Jedi became the first Sith Lords, and the balance of the Force changed forever.
9 SEVER FORCE
Jedi have the ability to bring together various aspects of their powers to sever other Force users' connection to the Force itself. It's not an unfamiliar trope in sci-fi and fantasy -- readers of The Wheel of Time will recognize it as stilling or gentling -- but it has troubling implications. The Jedi are a largely-autonomous order of holy warriors who have the ability to cut their foes off from their connection to something that the Jedi describe as the very essence of life itself.
Imagine being forced to lose all your will to live, to keep going, to be able to see the beauty in all things -- the loss of that alone would drive a rational person to the Dark Side, if they were able to recover their Force power. If they weren't, it would at least create an enemy of the Jedi forever.
8 THE FALLIBILITY OF RIGIDITY
The upside of a moral code is that it gives one a list of guidelines for how to live an upstanding, fulfilling life. Basically each religion provides a code for its adherents, and offers an explanation of the punishment for failure to adhere, often in the form of asking for forgiveness from a higher power. The Jedi had no system of sanctions -- if you did not adhere to the code, you were a heretic, more than halfway on the road to becoming a Sith.
This inability to allow for rehabilitation or redemption for mistakes drove otherwise powerful Jedi into the arms of the Dark Side, creating Sith Lords like Darth Vader, and Darth Revan. The Jedi have the worst habit of creating their own problems to help perpetuate the idea that they are infallible. Maybe that's why the Jedi have to die.
7 THE SITH GENOCIDE
After the Great Hyperspace War (the greatest name for a war there has ever been), about 5,000 years before the Battle of Yavin, the Supreme Chancellor of the Galactic Republic ordered the extermination of the Sith in the wake of their defeat in the war. This order encapsulated not just the lords of the Sith, the Dark Jedi who had risen to god-like status on planets like Korriban, but the native populations who worshipped these Sith Lords.
The Jedi could have tried to win the people of Korriban over, shown them that there were other ways than the Dark Side, that the balance of the Force exists with the Light alongside the Dark; instead, they chose to fear that which could have become an asset to them, and they stoked anti-Jedi sentiments in outer sectors that would turn on them decades later.
6 MILITARY LEADERSHIP
The Jedi claim to support peace, to use civilized weapons to help protect the galaxy from forces of brutality. But in every major military conflict for thousands of years before the Battle of Yavin, you will find Jedi leading the charge into battle -- you need look no further than Attack of the Clones or the Clone Wars TV show for some stunning visual evidence.
Even with a military history going back millennia, the Jedi have fallen prey to their own "wisdom" on a few occasions; during the Clone Wars, Yoda, Anakin Skywalker, and Obi-Wan Kenobi helped arm and train a rebel resistance force on a generally uninvolved planet to help them overthrow their king. Was it a noble cause? Perhaps. Was it the kind of thing the Jedi should be getting involved in, as the peacekeeping force of a sovereign body? Absolutely not.
5 NO ACCOUNTABILITY
Across the galaxy, anywhere there were concentrations of Jedi, there were Jedi Councils -- Jedi Masters who sat in contemplation of changes to the status of the Jedi, of tactical matters, and matters of state. The Jedi High Council was based on Coruscant before the Clone Wars and the rise of the Galactic Empire, and all the other councils answered to them. The Council theoretically answered to the Supreme Chancellor of the Galactic Senate, but in reality, the Jedi were an unchecked order of warrior-monks with laser swords and superhuman abilities to make war.
This lack of accountability led to political wrangling with Supreme Chancellor Palpatine, who was a complete and total pile of garbage who was duly elected by a body of sycophants who were thinking of themselves and not their constituents (a familiar story), which eventually, led to their own destruction.
In Knights of the Old Republic, audiences were introduced to the world of the Jedi and the Sith as it existed in the early days of the Republic, 4,000 years before The Phantom Menace. One presence who looms above the others is the conflicted Sith Lord, Darth Revan. Revan's history is long and complex, with his allegiances changing between Jedi, Sith, and his own plans to save the galaxy, but the troubling part was his "rescue" from the Dark Side at the end of Knights of the Old Republic.
He is rescued by Jedi Bastila Shan from his Darth Malak's treachery, and while he is recuperating, his mind is wiped so that he has no memory of his career as the galaxy's most feared Sith lord. The impulse to put Revan's personal demons at rest is noble, but the methodology is horrifying.
3 THE ARMY OF LIGHT
When the New Sith Empire had taken control of entire sections of the Outer Rim, a thousand years before the Battle of Yavin, some Jedi Knights took it upon themselves to reclaim the galaxy for the forces of good. After clearing sectors of Sith influence, they set themselves up as Lords in a new feudal system; Jedi Master Lord Hoth abandoned the Jedi Temple in order to gather these Lords, together with disaffected members of the Republic army, to form the Army of Light.
The Army was only active for a decade, and dissolved upon the end of the war, but it was the first great militarization of the Jedi, paving the way for the Jedi to become part of the Republic's military command structure, including in the Clone Wars, almost a thousand years later.
2 SINGLEMINDED PURSUITS AT THE EXPENSE OF LIVES
When the Jedi have a goal, they will pursue it until the end of their lives or the completion of said goal. Sometimes that means that the letter of their mission is accomplished, but the spirit falls by the wayside, leaving a wake of collateral damage that should give the Order pause. As one example among many: Anakin Skywalker's mother, Shmi -- when Qui-Gon Jinn and Obi-Wan Kenobi took young Anakin back to Coruscant to begin his Jedi training, they left Shmi behind, even though she was literally a slave to a flying wasp person.
This abandonment by the Jedi left her prey to the Sand People who killed her, and who indirectly set Anakin Skywalker on his path that ultimately led to Darth Vader. In situations where they could save one person to save hundreds more, Jedi make the wrong call almost every single time.
1 HIGH STANDARDS & ELITISM
The Jedi posit themselves as the moral authority of the galaxy. They live monastic lives in their strongholds, ruled over by Jedi Masters and smaller councils, while weighing in on the current sociopolitical conflicts facing the Republic. But the code of the Jedi relegates them to a strictly peacekeeping role, a non-interventionist position that precludes violence except for self-defense -- but they immediately take up military positions to combat the (theoretically) duly-elected Emperor.
Their inability to maintain these standards is what pushes good Jedi to the Dark Side; they want things that their ascetic lifestyle will not allow, and their failure to live up to their own rules wears them down. How many paths to the Dark Side start as Anakin's did, with noble intentions that were struck down by authority figures, rather than nurtured and directed? The story of the Light Side is a story of failure, at the end.