"Although Yoda clearly identifies fear, anger, and aggression as the dark side of the Force, and warns Luke not to use the strength that flows from them, as they will rule him and he will forever have to bear the consequences of what he has done under their sway, many fans and critics have distorted these teachings. The dark side is often asserted to be a malevolent metaphysical force or principle of wickedness that operates through fear, anger, and aggression. In the Expanded Universe novel Heir to the Empire, Timothy Zahn even altered Yoda’s teachings, writing, “Fear and anger, Yoda had often warned [Luke], were the slaves of the dark side.” In the 2000s, Matthew Stover spoke out against what he identified as the “dark-side-is-the-devil” perspective in the Expanded Universe, attempting to steer the narrative back toward Lucas’ canon. However, a few years later, in James Luceno’s The Unifying Force, Luke declared, “Anger by itself is not of the dark side,” and nevertheless insisted on fighting to “eradicate” the dark side, calling it “Evil” itself. Moreover, video games such as Knights of the Old Republic II portrayed drawing strength from the dark side as calling upon a mystical entity for magical powers through anger and aggression.
By the mid-2010s, such distortions had led to the formation of a primitive yet increasingly widespread interpretation that Jedi Knights were forbidden from feeling fear, anger, aggression, or other strong emotions altogether; Yoda’s teachings were reinterpreted as declaring such emotions “evil” in themselves, replacing valuable and practical psychological lessons on emotional regulation with a caricature of emotional repression. This interpretation resonated with those who may have been raised to believe that anger is always wrong, that feeling it is itself a moral failure, or that anger must be suppressed lest one face punishment in the afterlife - however, it does not match with the original cinematic portrayal."