History Main / GoodNeedsEvil

* {''Literature/TheStormlightArchive'': Discussed, where one of Literature/{{the Cosmere}}'s sixteen PiecesOfGod is Odium, the Shard of Hatred. Odium contends that his domain is actually Passion in all its forms and that his influence is necessary for humanity to strive and thrive; others say that that's a self-serving lie, and indeed, those most influenced by him tend to lash out and claim that their actions are NeverMyFault rather than act constructively. One person argues that the trope is {{inverted|Trope}}, as "He bears the weight of God's own divine hatred, separated from the virtues that gave it context".

* So long as there is ComicBook/TheSentry, so too must there be the Void.

* In ''Literature/InterviewingLeather'', Leather asserts this philosophy, claiming not only that this trope is true, but that the superheroes need villains not to just be "porn stars in capes." The protagonist, who is developing StockholmSyndrome, buys into it until [[HeroAntagonist Darkhood]] shows up and the series switches from {{Deconstruction}} to {{Reconstruction}}.

* ''VideoGame/CastlevaniaDawnOfSorrow'' has protagonist Soma Cruz harassed by [[OddlySmallOrganization a three-member cult called "With Light"]] that believes in this trope. For {{God}} to be Perfect Good, there must be Perfect Evil to oppose Him, in the form of the Dark Lord, a role that Soma's previous incarnation, {{Dracula}}, filled for [[VideoGame/CastlevaniaLamentOfInnocence just over a thousand years]]. Leader [[BigBad Celia Fortner]] decides that, if Soma is going to defy his destiny, as he did in the previous game ''VideoGame/CastlevaniaAriaOfSorrow'', then she'll just have to kill him or find [[TheLostLenore a way to change his mind]]. [[NonStandardGameOver If she succeeds]], it doesn't end well for her. In the True Ending, Arikado points out that Celia was misguided: If the world ever needs a Dark Lord again, one will appear naturally, as was the case with Dracula, even if that one winds up not being Soma.

* ''Anime/DragonBallSuper'': Gowasu, the Supreme Kai and guardian deity of Universe 10, states his opinion that this is true: if evil did not exist to provide conflict and challenges, then good people would have no opportunity to learn and grow. He includes the gods themselves in this, stating that they are not all-wise and even they have lessons they need to learn. This is in contrast to his apprentice Zamasu, who believes that evil should be eliminated entirely, which sounds alright until you realize that anyone who was anything less than perfectly good in Zamasu's eyes would be killed, which includes pretty much ''every mortal being in existence''.

* ComicBook/TheJoker, especially in the comics, practically defines himself in his opposition to Franchise/{{Batman}}, and feels they need each other, and their eternal struggle of good vs evil, to exist.
* Zoom, the second Reverse-[[ComicBook/TheFlash Flash]], works on the principle that he's making the heroes greater by giving them tragedy to overcome.

* During {{Satan}}'s song in ''WesternAnimation/SouthParkBiggerLongerAndUncut'', he sings "without evil there could be no good, so it must be good to be evil sometimes".

* ''Film/{{Legend 1985}}''. Just before he's apparently destroyed by the light:

* This is the entire ''point'' of ''Literature/VillainsByNecessity'' which essentially takes the ''Dragonlance'' example above and makes it happen, with the last villains having to set things right.

* Lord Vetinari explains it to Captain Vimes at the end of ''Literature/GuardsGuards'' this way:

* {{Discussed|Trope}} in ''Literature/TheStormlightArchive'', where one of Literature/{{the Cosmere}}'s sixteen PiecesOfGod is Odium, the Shard of Hatred. Odium contends that his domain is actually Passion in all its forms and that his influence is necessary for humanity to strive and thrive; others say that that's a self-serving lie, and indeed, those most influenced by him tend to lash out and claim that their actions are NeverMyFault rather than act constructively. One person argues that the trope is {{inverted|Trope}}, as "He bears the weight of God's own divine hatred, separated from the virtues that gave it context".

* In ''Series/{{Supernatural}}'' this is [[InvertedTrope inverted]] [[spoiler:by Amara the Darkness]]. She scoffs at the notion that she wants a world full of evil and asks Crowley if he seriously believes the world would be better off if ''everyone'' was evil. Crowley admits that corruptors like him would be bored and out of a job if there was no good left to corrupt. Evil needs Good.

[[folder:Religion and Mythology]]
* {{Defied|Trope}} by the apostle Paul in Literature/TheBible, against people who rationalized this as an excuse to keep doing things they know are sinful:

* St. Thomas Aquinas argues the inverse of this trope:

* A different spin on this is pretty standard Christian theology, though: simply put, you can't truly do good if you don't have a choice to do evil. Hence all the bad things in the world--if {{God}} got rid of them, he would be taking away our free will so we would just be robots. Of course, some object to this idea (for instance pointing out many bad things which don't come from free will, like diseases).
* Concerning the doctrine of {{hell}}, there are Christians who believe that without it, Jesus' sacrifice on the cross would be deemed all for nothing, and there would be no need for a savior if there is no hell to save people from.

* In ''Videogame/DiabloIII'' the titular character of the ''Rise of the Necromancer'' expansion believes in this trope, that the eternal conflict between light and dark is necessary for the stability and survival of the world.

* In ''Literature/{{Worm}}'', [[AwesomenessByAnalysis Tattletale]] has a variation on this which she calls "Cops and Robbers", arguing that the superheroes are like football teams, and the [[HarmlessVillain less dangerous villains]] provide opposition for the public to cheer against.

* ''WesternAnimation/JusticeLeague'': In "[[Recap/JusticeLeagueS2E11And12ABetterWorld A Better World]]", this is what sparked Justice Lord Superman's FaceHeelTurn. Lex Luthor [[HeroicHeelizationSpeech accused]] Superman of only ever keeping him around because he enjoyed being a hero and needed a villain to fight against, hence why he kept letting Lex live and did little to stop him from coming back to cause problems again. Superman calmly admits he's right and he ''did'' like being a hero... before frying Lex with heat vision, deciding that those days are over if this is where it leads.

* This trope is one of many, ''many'' theodicies presented as a response to the question of the "Problem of Evil", which asks "Why does an all-powerful, all-knowing, morally perfect God allow bad things to happen to good people?" Unfortunately the Problem is paradoxical in nature, so even if we assume evil is ''necessary'', it still leaves 'gratuitous evil' (such as cancer) unexplained. The idea that good is impotent without evil does not maintain free will, nor build people's character.
* The ancient philosophers Heraclitus and (following him) Chrysippus claimed that good without evil is ''logically'' impossible: "There can be nothing more inept than the people who suppose that good could have existed without the existence of evil. Good and evil being antithetical, both needs must subsist in opposition."[[note]]As quoted by Bertrand Russell in ''The History of Western Philosophy'', p. 257[[/note]]

You'd be lost without [[Characters/BatmanTheJoker me]]!"''

* ''WesternAnimation/JusticeLeague'': In the Justice Lords' universe, this is what sparked Superman's FaceHeelTurn. Lex Luthor [[HeroicHeelizationSpeech accused]] Superman of only ever keeping him around because he enjoyed being a hero and needed a villain to fight against, hence why he kept letting Lex live and did little to stop him from coming back to cause problems again. Superman calmly admits he's right and he ''did'' like being a hero... before frying Lex with heat vision, deciding those days are over if this is where it leads.

* ''[[VideoGame/CastlevaniaChroniclesOfSorrow Castlevania: Dawn of Sorrow]]'' has protagonist Soma Cruz harassed by [[OddlySmallOrganization a three-member cult called "With Light"]] that believes in this trope. For {{God}} to be Perfect Good, there must be Perfect Evil to oppose Him, in the form of the Dark Lord, a role that Soma's previous incarnation, {{Dracula}}, filled for [[VideoGame/CastlevaniaLamentOfInnocence just over a thousand years]]. Leader [[BigBad Celia Fortner]] decides that, if Soma is going to defy his destiny, as he did in the previous game ''Aria of Sorrow'', then she'll just have to kill him or find [[TheLostLenore a way to change his mind]]. [[NonStandardGameOver If she succeeds]], it doesn't end well for her. In the True Ending, Arikado points out that Celia was misguided: If the world ever needs a Dark Lord again, one will appear naturally, as was the case with Dracula, even if that one winds up not being Soma.

* ''[[VideoGame/CastlevaniaChroniclesOfSorrow Castlevania: Dawn of Sorrow]]'' has protagonist Soma Cruz harassed by [[OddlySmallOrganization a three-member cult called "With Light"]] that believes in this trope. For {{God}} to be Perfect Good, there must be Perfect Evil to oppose Him, in the form of the Dark Lord, a role that Soma's previous incarnation, {{Dracula}}, filled for [[VideoGame/CastlevaniaLamentOfInnocence just over a thousand years]]. Leader [[BigBad Celia Fortner]] decides that, if Soma is going to defy his destiny, as he did in the previous game ''Aria of Sorrow'', then she'll just have to [[KillAndReplace kill him]] or find [[TheLostLenore a way to change his mind]]. [[NonStandardGameOver If she succeeds]], it doesn't end well for her. In the True Ending, Arikado points out that Celia was misguided: If the world ever needs a Dark Lord again, one will appear naturally, as was the case with Dracula, even if that one winds up not being Soma.

* ''[[VideoGame/CastlevaniaChroniclesOfSorrow Castlevania: Dawn of Sorrow]]'' has protagonist Soma Cruz harassed by [[OddlySmallOrganization a three-member cult called "With Light"]] that believes in this trope. For {{God}} to be Perfect Good, there must be Perfect Evil to oppose Him, in the form of the Dark Lord, a role that Soma's previous incarnation, {{Dracula}}, filled for [[VideoGame/CastlevaniaLamentOfInnocence just over a thousand years]]. Leader [[BigBad Celia Fortner]] decides that, if Soma is going to defy his destiny, as he did in the previous game ''Aria of Sorrow'', then she'll just have to kill him or find [[TheLostLenore a way to change his mind]]. [[NonStandardGameOver If she succeeds]], it doesn't end well for her.