-> ''"A man may die, nations may rise and fall, but an idea lives on. Ideas have endurance without death."''
-->-- '''UsefulNotes/JohnFKennedy'''

[[Film/{{Inception}} What is the most resilient parasite?]] An idea. A single idea from the human mind can build cities, rewrite all the rules, and transform the world. Neither armies, nor dictators, nor even mortality have power over them; people die, but their ideas do not.

In fiction, we get heroes dying but hope passed onto the audience by knowing that somehow his idea has lived on. Sometimes the hero is [[InspirationalMartyr a martyr]] and his death is a [[MyDeathIsOnlyTheBeginning beginning]] as people use it for inspiration; they are throwing off some kind of [[ThereAreFourLights mind-breaking torture attempt]] to show that the forces of fascism can't control them. A book of philosophy or some diary may have survived him, or one of his inner circle may tell his tale and so the story ends on a happy note, but not too happy. Our story is sad but the tide of inevitable revolution will come.

The TropeNamer is American civil rights activist Medgar Evers, who stated that "you can kill a man, but you can't kill an idea." He was later shot dead by a [[UsefulNotes/KuKluxKlan Klansman]], but the civil rights movement endured.

SuperTrope of CantStopTheSignal. The characters who pass on the idea are likely {{Doomed Moral Victor}}s. Likely to inspire an InnocentBystander to make a DefiantStoneThrow. Compare WeAreEverywhere, for those bad ideas that can't be killed, and the [[MindVirus "Neurovirus" or "Memetic Science"]] for bad ideas that deserve to die but are too sentient and/or too contagious to be killed by law of [[MindWipe morality]], [[{{Thoughtcrime}} man]] or [[TheHeretic god]] (and don't expect TimeTravel or BigDamnVillains to fix it either).



[[folder:Anime & Manga]]
* ''Manga/OnePiece'':
** Both Gold Roger and Dr. Hiruluk died embracing this ideal. Gold Roger manages to start the Golden Age of Piracy.
** In the face of a Marine victory which could have snuffed out the Golden Age of Piracy, [[spoiler:Whitebeard, with his last breath, proclaims that Roger's treasure does exist, thus reigniting the idea once more]]. The Marines were not happy with this.
** The villains of the Fishman Island arc attempt to invoke this, hoping to have their grudge against humans carry to the next generation by killing as many people as they can (humans and Fishman alike) when it looks like they're not going to win. As it turns out, you ''can'' kill an idea, if you do it with a contrary one. Luffy's human (though we use that loosely) crew fighting to protect Fishman Island causes that idea to blow up in their faces.
* Happens in ''Anime/CodeGeass''. Lelouch's ideals were to fight against injustice and tyranny caused largely by the Britannian Empire. Later, he causes changes in the empire itself, and in the end helps make the world a better place for almost everyone, [[spoiler:at the cost of his life and reputation, while passing on the torch of Zero to Suzaku.]]
** Earlier in the second season, Lelouch pulls off a SugarWiki/MomentOfAwesome by exploiting this trope. When cutting a deal with the Britannians, they want to know if he's the original and he gets them to agree that it doesn't matter, because anyone who wears the costume and espouses the beliefs is "Zero". Then when the Britannians announce that they're formally exiling Zero from Japan, a million of his supporters put on Zero costumes, meaning the Britannians are forced to exile all of them, giving him a million-strong army (the only reason why that same million [[WhyDontYouJustShootHim isn't just exterminated on the spot on the off chance that the real Zero is among them and to give all other rebels a lesson]] (and they were ''seriously'' entertaining the idea) is because the one in charge (Suzaku) still held a degree of HonorBeforeReason and had given his word that this agreement would be upheld no matter what).
* After the formation of the team Dai Gurren in ''Anime/TengenToppaGurrenLagann'', [[spoiler:Kamina]] dies in middle of the battle [[AnyoneCanDie against every prediction]]. During the rest of the series, he is remembered constantly as a role model for the main cast, especially Simon... to the point that the new futuristic city is called [[spoiler:Kamina City]].
* In ''VideoGame/FZero GP Legend'', before his base is destroyed, [[BigBad Black Shadow]] yells that hell never die, nor will his dreams. Captain Falcon [[ShutUpHannibal responds]] by [[AscendedMeme Falcon Punching]] him.

[[folder:Comic Books]]
* ''ComicBook/VForVendetta'': The anarchist title character, to Eric Finch, who's just shot him:
-->'''V:''' Did you think to kill me? There's no flesh or blood within this cloak to kill. There's only an idea. Ideas are bulletproof.
* In ''ComicBook/ThreeHundred'', Xerxes angrily declares that once he defeats the Spartans, he will completely destroy them and wipe out any trace of them from history.
-->'''Leonidas:''' The world will know that free men stood against a tyrant, that few stood against many and, before this battle is over, that even a god-king can bleed.
* Bruce Wayne isn't the only one who's taken on the role of Franchise/{{Batman}}. Many incarnations of the character support the theme of Batman being more of an idea than a single person (especially ''Film/TheDarkKnightSaga'').
* ''ComicBook/{{Watchmen}}'': [[spoiler:Rorschach's Journal is heavily implied to have been published after the events of the graphic novel, revealing Ozymandias' master plan to the wide public, even though Dr. Manhattan killed Rorschach SPECIFICALLY SO THAT IT DOESN'T HAPPEN]].
-->'''Rorschach:''' Never compromise. Even in the face of Apocalypse, never compromise. [[spoiler: Seconds after that, Dr. Manhattan blows him up.]]

[[folder:Comic Strips]]
* ''ComicStrip/ThePhantom'': Go ahead, try to kill him. You might succeed, it won't help.

* Evil example done in the prologue to ''Fanfic/ShadowchasersConspiracy''; in a flashback set in 1945 during the siege of Berlin, an American Chaser named Anderson Steading and two others have cornered a Nazi officer who is, in reality, [[HumanoidAbomination an illithid.]]
-->'''Steading:''' I'm not warning you again. As of this moment, I'm no more impressed by the title of 'Fuhrer' than I am of the powerless weakling an illithid is when it can't use its psychic powers. Now put your slimy hands up or I swear I'll send you to Hell to meet him.
-->'''Illithid:''' I don't care… No matter how many of us you pigs kill… ''(draws a knife)'' …''[[DiscussedTrope you can't kill an idea!]]''
-->''[[SuicideByCop (Lunges, but Steading and his men open fire, killing him.)]]''
-->'''Steading:''' Maybe... [[PostMortemOneLiner But an idea can kill you…]]

[[folder:Films -- Live-Action]]
* ''Film/TheDarkKnightSaga'':
** Bruce Wayne uses this sort of reasoning when devising his future role in ''Film/BatmanBegins'', as advised by Henri Ducard. A man acting just by himself as a man can be killed, bribed, or discouraged, but by becoming a 'symbol', the man becomes "more than just a man"; even if he dies, the symbol lives on to inspire others. [[Franchise/{{Batman}} Guess what symbol Bruce eventually settles on...]] [[spoiler:And it's heavily implied that Ra's Al Ghul has operated by the same principle.]]
** It plays out again in ''Film/TheDarkKnightRises''. [[spoiler:Bruce Wayne fakes Batman's death and retires from superhero-ing, but he leaves the keys to the Bat Cave with detective John "Robin" Blake, so Blake can be the hero that Gotham needs.]]
* In ''Film/{{Casablanca}}'', Victor Lazslo tries to assert this about LaResistance against the Nazis. The film itself does a good job of illustrating the concept. Unfortunately ThoseWackyNazis also have ideas, and ones that Lazlo is kinda, you know, trying to kill.
* Played with in ''Film/{{Dogma}}'', where Rufus comments that "ideas" are malleable and can change and possibly even die out. "Beliefs," which are strengthened ideas, are much harder to even change, let alone kill. It also places a spin on it in that the fact that a belief is hard to 'kill' is not necessarily a good thing if the belief is not a good one, or if the belief has become an overly rigid dogma.
* ''Film/{{Inception}}'' addresses this and emphasizes why it is so hard to plant one. The title refers to the act of doing so, but the main obstacle is that [[GladIThoughtOfIt the subject has to believe it's their own idea]] for it to stick. The next complication is that the idea will grow to define their entirely life... even to suicidal extremes.
* ''Film/VForVendetta'' had an epic one near the end. After taking dozens of bullets and killing a dozen men before they could finish reloading (as per his BadassBoast), V approaches The DragonInChief, who asks, in disbelief, "WhyWontYouDie!" His response? "Beneath this mask is more than flesh; beneath this mask there is an ''idea'', Mister Creedy -- and ideas. Are. ''[[PunctuatedForEmphasis Bulletproof.]]''" [[spoiler:The literal bullet proof vest helped, if only for a while; he died shortly thereafter to his wounds.]]
* ''Film/{{Braveheart}}'': William Wallace, right after being [[spoiler: racked, stretched by horses, and disemboweled]], defiantly yells ""FREEEEDOOOOOOMMM!"'
* ''Franchise/TheMatrix'' features this trope quite heavily. The idea that the human mind cannot truly function without a real choice plays into the design of the Matrix itself and the cycle of the One as a means for the machines to keep the human population under control. The entire trilogy revolves around breaking this control for true freedom.
* ''Film/{{Equilibrium}}'': "A heavy cost. I pay it gladly." Partridge refuses to give in to Preston, deconstructing the meaning of a system without emotion. Being aware that he has just committed a sense offence, he faces death in the most composed way possible as a form of his defiance, because he'd rather die for his beliefs than be committed to a corrupted establishment. Fair to say, his words continue to reverberate as Preston unravels the truth and the Resistance gain a chance to seep through.
* ''Film/IronMan'':
** ''Film/IronMan1'' uses a villainous version. It's one thing if you want your idea to spread and inspire people, but what if you want to keep your idea -- like, say, the key to PoweredArmor -- to yourself to avoid it being abused?
--->'''Stane:''' You think that just because you have an idea, it ''belongs'' to you?
** ''Film/IronMan2'' confirms this. Iron Man's existence made the whole world realize that PoweredArmor is a viable and powerful weapon. Tony initially downplays the problem because he's one of the only people who can actually make a reliable suit. Unfortunately, the villain of the movie is also smart enough to make his own suit, and he's got a grudge against Tony.
** Vanko believes he ''has'' killed an idea, having attacked (and nearly killed) Tony. The idea, specifically, being that Iron Man can't be beaten; "If you could make God bleed, people would cease to believe in Him. There will be blood in the water, the sharks will come. All I have to do is sit back and watch as the world consumes you." [[JerkassHasAPoint He's kind of right.]]
* The BadFuture in ''Film/XMenDaysOfFuturePast'' is set off by Mystique killing Trask, since he was the head of the Sentinel program. Killing him only convinced others to continue his work, and the future happened. When it comes down to it, the {{aesop}} is that you cannot kill an idea, but must discredit it. The inverse occurs when [[spoiler:she spares him and saves the President. He instead gets arrested for trying to sell military secrets to the North Vietnamese government at the Paris Peace Accord, causing the program to be shelved.]]
* ''Film/BenHur1959''. Messala takes command of the Jerusalem Garrison and has this exchange with the former commander Sextus. "Yes Messala but how do you control whats up here? (points to his head) How do you fight an idea? Especially a new idea." Later, Messala has a response to this trope. "Sextus, you asked how to "fight an idea" Well I'll tell you how... With another idea."
* In ''Film/AndQuietFlowsTheDon'', Podtyolkou the Bolshevik says this right before his execution, telling the crowd that they'll be sorry later, and that all Russia will be Bolshevik.

* Averted in ''Literature/NineteenEightyFour'', in an inversion of the inspirational "the hero lives on" type of endings: [[spoiler:Winston is allowed to live long enough to be forced to admit that he really does love Big Brother before being killed, so the audience knows that in no way were the ideas of The Party overcome.]] In fact, the entire concept of NewSpeak is meant to defy this trope, by [[LanguageEqualsThought systematically eradicating even the words that could express ideas]] such as liberty, rebellion, or individuality, which run counter to the ideological orthodoxy of the Party.
* PlayedForLaughs in ''Literature/{{Discworld}}'' novels on several occasions, frequently with people using rumors that once they get started can not be stopped. In ''Discworld/InterestingTimes'', for instance, Rincewind goes around telling soldiers that ''in no way'' are there any invisible vampire ghosts about to attack them in the following battle and [[SuspiciouslySpecificDenial there are ''absolutely not'' 2,300,009 of them]].
** Of course Discworld takes it literally many times. ''Discworld/WitchesAbroad'' introduces the idea that on the Discworld, stories have not only memetic influence, but [[TheoryOfNarrativeCausality are a law of nature]]. In ''Discworld/SoulMusic'' and ''Discworld/MovingPictures'', the immortal idea (rock music and movies, respectively) is the BigBad.
** In ''Discworld/ThiefOfTime'' the Glass Clock, which destroyed all of history in the past, was removed from any books by the History Monks, but something that strong still seeped through and found its way into children's stories.
* ''Literature/BelisariusSeries'': Used first seriously and then humorously. Belisarius starts a rumor about sexual prowess and general horniness of the Kushans in order to get Kungas and his men pulled away from their guard duty of a captured princess. Their incompetent replacements are easily dispatched and allow her to be rescued. Later, once the confused Kushans find out about the origin of the rumor, they then take delight in spreading it themselves.
* ''Literature/TheDresdenFiles'' novella ''Backup'' goes into a bit of detail about The Oblivion War, a war waged, essentially, against ideas. Specifically, the memory of some unpleasant old gods who can't do anything if humans remain blissfully unaware of their existence. We don't get a ''lot'' of information, but since the antagonist is a cultist of said gods, and Thomas (the novella protagonist) mentioned the war has been ongoing for thousands of years, it fits.
** Actually, the Oblivion war could be a subversion, because it's implied that the Venatori actually ''have'' killed ideas over the course of the conflict. As well as putting others on life support.
* In the ''Literature/EighthDoctorAdventures'', a group of Time Lords (the Celestis) take this concept literally, and [[AscendToAHigherPlaneOfExistence convert themselves into ideas]] for this very reason. Unfortunately for them, a later book reveals that the Franchise/{{Whoniverse}} also contains [[AbstractEater creatures]] which ''can'' kill -- and eat -- ideas.
** The heavily associated spin-off Literature/FactionParadox basically ''[[UpToEleven is]]'' this trope.
* This is the crux of [[spoiler:Kelsier]]'s ThanatosGambit in ''Literature/{{Mistborn}}''. He purports himself as a figure of legend and a symbol of evolution, so that when he is killed, a vengeful religion rises up immediately to complete his work in his name.
* In ''Literature/{{Fatherland}}'' (rephrased): "Cut a clearing in the forest of your mind, the trees are just waiting to reoccupy it."
* Invoked in "Literature/SecretCity":
-->'''Eligor''': You cannot kill an idea!\\
'''Santyaga''': Yes. We prefer to exterminate those who carry them. ''[stabs him]''
* In ''Literature/ItCantHappenHere'', the totalitarian government never completely stamps out people's longing for freedom and dignity. Revolts erupt across America as people take back areas from Haik's forces. Doremus in particular exemplifies this trope, continuing the struggle after having lost loved ones, endured torture and incarceration, and lived in lonely exile.
-->And still Doremus goes on in the red sunrise, for a Doremus Jessup can never die.
* ''Literature/TheStormlightArchive'':
** Spren are living ideas. The more common ones are things like wind and rot and anger, but more powerful and intelligent ones are spirits of honor and lies and law. Normally, killing any of these is essentially impossible, but there is one way to kill them on an individual level: When they bond with a human (which grants that person special powers), the spren gains the ability to maintain their sentience in the Physical Realm, but they also become vulnerable. If the human does not hold to their oaths (the precise oath varies depending on the spren), the spren will weaken and eventually lose their sentience. Actively breaking their oaths will actually kill the spren. They can be brought back if the human re-swears their oaths.
** [[spoiler:The spren who were bonded to the old Knights Radiant were all killed during the Recreance, when all the knights broke their oaths at once. Since the spen were also their [[SoulCuttingBlade Shardblades]], they were locked in that form when they died, and the kingdoms of the world have been using the corpses of spren as the most dangerous and valuable objects for millennia. A non-Radiant can bond with a Blade, giving the spren a simulacrum of life for a moment (enough to be [[SummonToHand summoned and dismissed at will]]), but no more. Truly bringing them back to life has been implied to be possible but very difficult, as their original bonded knights are long dead. According to WordOfGod, it would not only require a wielder of the dead blade to swear the oaths of the order of the Knights Radiant the spren was associated with but something more to forge a new bond with the spren and heal their mostly destroyed minds.]].
* "Souvenir" by Philip K. Dick. [[spoiler: Everyone on Williamson's World is [[KillEmAll killed]], but one of the people involved brings some trinkets from it home and gives them to his son, and the story ends with the son looking at them with "a strange light in his eyes".]]
* The Franchise/StarWars ExpandedUniverse will ''never'' be rid of the [[ProudWarriorRace Mandalorians]], why? Well, in the words of Mandalore the destroyer:
--> ''"Here's why you can't exterminate us,'' aruetii[[note]][[YouAreTheTranslatedForeignWord refers to someone not Mandalorian, or traitors.]][[/note]] . ''We're not huddled in one place — we span the galaxy. We need no lords or leaders — so you can't destroy our command. We can live without technology — so we can fight with our bare hands. We have no species or bloodline — so we can rebuild our ranks with others who want to join us. We're more than just a people or an army, aruetii. We're a culture. We're an idea. And you can't kill ideas — but we can certainly kill you."''


[[folder:Live-Action TV]]
* In ''Series/BabylonFive'', at the climax of the Vorlon-Shadow War Delenn and Sheridan point out that, even if they and their coalition are killed, their assertion that the younger races no longer ''need'' the First Ones is true. All the First Ones can do is subjugate them, not "teach" them as the two sides insist they want to.
* ''Series/DoctorWho'': The Doctor was able to destroy a prime minister with this trope. He only needed to say six words to an aide. [[spoiler:"Don't you think she looks tired?"]] He doesn't die [[spoiler:(quite the opposite, really)]], and the PM isn't necessarily evil, but he does [[InvokedTrope use the principle of an idea being unkillable]].
* ''Series/StarTrekTheNextGeneration'':
** "[[{{Recap/StarTrekTheNextGenerationS6E21RightfulHeir}} Rightful Heir]]": Chancellor Gowron talks about the symbolic effect of the return of the Klingon GodEmperor.
--->'''Gowron:''' Kahless has been dead for a thousand years; but the idea of Kahless is still alive. Have you ever fought an idea, Picard? It has no weapon to destroy, no body to kill.
*** Later in the episode, the same argument is used to convince Gowron to let Kahless be a figurehead Emperor rather than oppose him. When Kahless counters that this Kahless is a clone, Worf points out that it won't matter to a good number of Klingons, who will still see it as reincarnation, and would only result in fracturing the Empire. Gowron is forced to, reluctantly, kneel before Kahless (even though Gowron is still in charge).
** In the two-part episode "Birthright", Worf discovers a Romulan prison camp where Klingons and Romulans have learned to live together in peace. However, he finds that the Klingon children are not informed about their heritage. The Romulan leader, Tokath, finds him a threat to this peace, and demands that Worf stop or else he'll get executed. Worf tells him he is content to FaceDeathWithDignity for this reason.
--->'''Worf:''' I am being executed because I brought something dangerous to your young people. Knowledge. Knowledge of their origins. Knowledge of the real reasons you are here in this camp. The truth is a threat to you.
* ''Series/StarTrekDeepSpaceNine'': "[[{{Recap/StarTrekDeepSpaceNineS06E13FarBeyondTheStars}} Far Beyond the Stars]]". Benjamin Sisko, dreaming that he's a science fiction writer in the 50s, reacts rather badly to having his story pulped because it has a black Captain.
-->'''Sisko:''' You can deny me all you want but you can't deny Ben Sisko – He exists! That future, that space station, all those people – they exist in here! In my mind. I created it. And everyone of you knew it, you read it. It's here. Do you hear what I'm telling you? You can pulp a story but you cannot destroy an idea, don't you understand, that's ancient knowledge, you cannot destroy an idea. That future – I created it, and it's real! Don't you understand? It is real. I created it. And it's real! It's real!
* ''Series/{{Sherlock}}'':
** In the episode, "[[Recap/SherlockS02E03TheReichenbachFall The Reichenbach Fall]]", Donovan and Anderson manage to [[spoiler:sow the seeds of doubt regarding Sherlock's authenticity as a (relatively) aboveboard detective]]. When Lestrade [[spoiler:comes to warn Sherlock of his impending arrest]]:
--->'''Sherlock:''' After all, you can't kill an idea, can you? Not once it's made a home... ''(Taps Lestrade's forehead)'' There.
** That's the whole point of the episode, with [[spoiler:Moriarty]] managing to convince ''everybody'' that Sherlock is [[spoiler:a fraud and that even "Moriarty" is a paid actor hired by Sherlock]]. He proves it by [[spoiler:killing himself, forcing Sherlock to jump from a rooftop lest all his friends die]].
** This is then reversed in the "[[Recap/SherlockS03E01TheEmptyHearse The Empty Hearse]]" which shows that given enough time, cooler heads were able to re-examine the subject and found major faults in the original theory. Once discredited, the idea quickly dies off and [[spoiler: when Sherlock is revealed to be still alive, the pubic embraces him once again as a hero.]]
* On ''Series/TheDailyShow'', Mo Rocca suggested that to adequately fight the War on Terror, what America needs is "a bomb that destroys ideas".
* {{Discussed}} in a ''Series/{{NOVA}}'' episode on radicalization, [[http://www.pbs.org/wgbh/nova/military/15-years-terror.html "15 Years of Terror"]]. One of the interviewees points out that the only thing that kills a bad idea is a ''better'' idea.
* In ''Series/TheOuterLimits1995'''s episode "[[Recap/TheOuterLimits1995S4316FinalExam Final Exam]]", this trope is {{discussed}} in relation to the [[HumansAreTheRealMonsters moral]] and environmental implications behind [[spoiler:cold fusion [[NukeEm bombs]] and the advance of [[ScienceIsBad technology]] overall]]. When Martin questions how Todtman reached his breakthrough with [[spoiler:cold fusion technology before the {{HereWeGoAgain}} ending in a different university implies the same scenario will take place ]]:
--->'''Todtman: '''So simple once they ask the right question, only they're expecting the wrong answer.

* Music/PeterGabriel invokes this trope in the song "Biko", a tribute to [[UsefulNotes/TheApartheidEra South African martyr Steven Biko]], with following lyric:
-->"You can put out a candle, but you can't put out a fire,\\
Once the flames begin to catch, the wind will blow it higher."
* The point of the song "I Dreamed I Saw Joe Hill Last Night", as recorded by Paul Robeson, Joan Baez and others.
* German folk song ''Die Gedanken sind frei'' - (''Thoughts are free'') is all about this. Sophie Scholl, a member of the [[LaResistance White Rose]], famously played the song on her flute outside the walls of Ulm prison in 1942, where her father Robert had been detained for calling Hitler ''a scourge of God''.

* ''The New Moon'': In the Finale Act I, after the masks come off and Robert is captured:
-->'''Ribaud''': So, Monsieur Beaunoir, the sooner your ship can set sail, the sooner we can treat Paris to a most amusing execution.\\
'''Robert''' ''(as men sing "Stouthearted Men" offstage)'': All right, Ribaud, you have won, but long after my amusing execution something will live after me. Listen! You hear that--that song, that spirit will destroy you and your king, and all the cruelty you stand for!

[[folder:Video Games]]
* ''Franchise/AssassinsCreed'':
** In ''VideoGame/AssassinsCreedII'', one of the Codex pages reveals that Altaïr mused on this subject more than once, noting that the [[UsefulNotes/TheKnightsTemplar Templars]] waged war by seeking to win over the hearts and minds of people with ideas, rather than more conventional weapons. This made it rather difficult for the [[TheHashshashin Assassins]] to fight back... But it also makes it rather difficult for the Templars to exterminate them.
--->'''Altaïr Ibn-La'Ahad''' ...how does one wage war against a concept? It is the perfect weapon. It lacks a physical form yet can alter the world around us in numerous, often violent ways. You cannot kill a creed. Even if you kill all of its adherents, destroy all of its writings – these are a reprieve at best. Some one, some day, will rediscover it. Reinvent it. I believe that even we, the Assassins, have simply re-discovered an Order that predates the Old Man himself...
** Taken UpToEleven in ''VideoGame/AssassinsCreedIII'' by [[spoiler:Haytham Kenway]] when fighting Connor; while the Assassins are literally born of lifetimes of discipline and self-study, the Templars grow like weeds no matter what the Assassins do because EvilIsEasy and EvilPaysBetter. The Templars are even more resilient than the Assassins because they're not even an idea - they're the ''absence'' of one.
--->'''Haytham:''' Even when your kind appears to triumph, still, we rise again. And, do you know why? It is because the Order is born of a ''realization.'' We require no ''creed!'' No indoctrination by desperate old men. All we need is that the world be ''as it is.'' And this is why the Templars will never be destroyed!
* Invoked in ''VideoGame/DeusEx'' when the terrorist leader says 'You can't fight ideas with bullets'. A [[CentralTheme running theme]] throughout the game. "A single artist, a single general, a single hero or a single villain may all die, but it is impossible to kill a people, a nation, an idea -- except when that idea has grown weak and is overpowered by one that is stronger." --The Doctrine of the Mighty
* In ''VideoGame/MadWorld'', XIII says that he wants to see an idea die. A culture. A religion. Any idea. [[spoiler:He got his wish. [[AvertedTrope The]] BloodSport [[AvertedTrope Deathwatch is dead.]]]]
* ''VideoGame/KnightsOfTheOldRepublicIITheSithLords'': This is one of Kreia's favorite tropes. She points out that killing men is easier than killing belief and that Revan, in the process of fighting the Mandalorians, [[HeWhoFightsMonsters adopted Mandalorian tactics and their intolerance for the "weak."]] She also points out that every time the Jedi and Sith fight each other to near-extinction, the ''ideals'' of either side still remain as strong as ever, waiting for their chance to strike back in revenge and dooming the galaxy to endless warfare.
** Subverted with Kreia herself. Not being the most social woman, her worldview ultimately died with her, since the only person she bothered teaching it to didn't share it (plus she had a nasty habit of killing those to whom she preached). No other character in the Star Wars universe ever expresses the same view on the Force ever again.
* ''VideoGame/TacticsOgre'':
-->'''Sisteena:''' If you want to kill me, go ahead. I may die but my ideals will live on!
* [[VideoGame/VictoriaAnEmpireUnderTheSun The Victoria Games]] by Creator/ParadoxInteractive, spanning from the early 19th century (specifically, 1836) to right before UsefulNotes/WorldWarII has this in the game-play where your population will get [[SarcasmMode silly ideas]] such as minimum wages and universal suffrage on their minds. Starting revolts if the pressure of having enough people saying they want it isn't enough.
** Victoria 2 adds a suppression mechanic to stop ideas you find dangerous. However, it is a temporary reprieve - the suppressed movement will most likely show up again after a few years and be more radical and inclined to violence.
* In ''VideoGame/MetalGearSolid2'' the main bad guys The Patriots invoke this trope to justify why they will always exist. They (through their AI programmed to talk to Raiden) explain to Raiden that they are the very moral and intellectual consciousness of the United States of America, every idea that comes into the collective consciousness of each American citizen originates from them. You can't kill the Patriots as an organization because they aren't simply a business that can be shut down but an idea in and of itself.
* In ''VideoGame/MassEffect3'' the Illusive Man cites this trope as the reason Cerberus will never fall, even with their headquarters in ruins and their forces scattered.
* Invoked in ''VideoGame/TheElderScrollsVSkyrim'' by Ulfric Stormcloak. Partially subverted if you complete the Imperial Legion questline, as while there would still be holdouts, most would eventually lay down their arms and return to their homes.

[[folder:Web Comics]]
* Remus Shepard had a go at this in ''Webcomic/IndefensiblePositions'', then deconstructed it in ''Webcomic/GenocideMan''. In the former ideas are actually living creatures known as demons, but are [[GodsNeedPrayerBadly dependent on belief]] from humans to survive. However the protagonist of the latter argues that an idea can be killed, and that some ideas [[http://www.genocideman.com/?p=88 ''should'' be killed]]--even if the only way to do so is to slaughter every single person who holds the idea.

[[folder:Web Original]]
* Invoked in the ''[[Roleplay/GlobalGuardiansPBEMUniverse Global Guardians]]'' character Amnesty, an enormously powerful superhero who regularly opposes dictatorships and oppression world-round and is known for doing things like destroying entire armies in order to save refugees caught in a war zone. She's been "killed" any number of times by the people she opposes, but keeps popping back up fresh as a daisy because she is the AnthropomorphicPersonification of Hope, Kindness, Mercy, and Compassion and no matter how dark the world gets, [[HopeSpringsEternal you can't kill hope]]!
** Unfortunately, the same can be said for the Blood Red King, Amnesty's fiercest rival and the most feared villain in the ''[[Roleplay/GlobalGuardiansPBEMUniverse Global Guardians]]'' universe: he is the AnthropomorphicPersonification of Terror, Despair, and Man's Inhumanity to Man... something that has proven just as impossible to kill as hope.
* Wiki/SCPFoundation: "Tell me, little girl, how does one kill an idea?" "With better ideas." [[spoiler:Unfortunately for the good guys, they don't have one. The end.]]

[[folder:Western Animation]]
* Parodied in ''WesternAnimation/{{Futurama}}'': "You can crush me but you can't crush my spirit!" *crushed by giant claw* "Ow! My spirit!"

[[folder:Real Life]]
* The whole basis for [[http://knowyourmeme.com/memes/the-game The Game.]]
* Che Guevara's last words, [[UnreliableNarrator according to at least one biography]]:
--> I know you have come to kill. Kill me if you wish, coward, but know that you can only kill a man.
* There were several sects of early Christians that are only known about by official church writings condemning them. In some cases we only have the names and there must have been others where even that hasn't survived. Of course since we don't know what their ideas were it is impossible to say whether those ideas were killed, absorbed by the Catholic Church or recycled by better known groups. (That's a red herring, as many of those ideas would have had to also have been "absorbed" by the Eastern Orthodox Church, the Assyrian Church of the East, and the Oriental Orthodox Church)
* [[https://en.wikiquote.org/wiki/Joseph_Stalin In a 2001 book of "Quotations for Public Speakers", the US ex-senator Robert Toricelli]] [[BeamMeUpScotty almost certainly incorrectly claimed that]] UsefulNotes/JosefStalin had said:
-->Ideas are more powerful than guns. We would not let our enemies have guns, why should we let them have ideas?
* Government propaganda targeted at an enemy intentionally invokes this trope, especially during wartime.
* Opponents of the WarOnTerror and War On Drugs invoke this trope as one of their points. [[RuleOfCautiousEditingJudgement We shall not go any further.]]
* Generally, outside attempts to forcibly repress or destroy an idea are doomed to fail, but ideas can destroy ''themselves'' if they inspire widespread revulsion and their practitioners are doing horrible things.
* A legal punishment in ancient Rome was ''[[http://en.wikipedia.org/wiki/Damnatio_memoriae damnatio memoriae]]'', which was [[UnPerson an attempt to erase a political figure completely from history after his or her death]]. Their faces would be removed from portraits, statues damaged, and anything mentioning their name would be destroyed or erased. This is extremely difficult to pull off completely - for instance, we have some surviving busts of Publius Septimius Geta, denarii featuring his image, and a wealth of information about his personality, tastes, family politics and eventual assassination - and obviously it's impossible to know if a complete damnatio memoriae ever occurred.
** Possibly an ancient example of the StreisandEffect.
* A saying from the Norse ''Literature/PoeticEdda'', attributed to [[Myth/NorseMythology Odin]]:
-->''Cattle die, kinsmen die, we ourselves also die; but the fair fame never dies of him who has earned it.''
* A similar saying is utilized in the Occupy protests, by the slogan "You cannot evict an idea". Possibly a subversion, given that Occupy got stuck with the reputation of being a bunch of rich kids trying to convince the poor they were one and the same, a case of an idea eating itself; haven't heard much about Occupy lately, have we?
* Tommy Douglas, former premier of Saskatchewan and founding leader of the New Democratic Party, ended his "Mouseland" parable as such:
-->''But I want to remind you: that you can lock up a mouse or a man but you can't lock up an idea.''
* 2012 Presidential Candidate UsefulNotes/RonPaul has stated this about his ideas:
-->''"Ideas spread, you can't stop them. An idea whose time has come cannot be stopped by any army or any government!"''
* Black Panther Fred Hampton once said that "You can kill the revolutionary, but you can't kill the revolution."
* Creator/{{Plato}} was a pioneer of this trope. His philosophizing posited 'forms' existing independently of the real world, i.e. every chair may look different, but we recognize them as 'a chair' because they all reflect form of the eternal chair. Hence, mankind will never forget how to make chairs because the idea exists separately from any one man. Things like 'justice', 'virtue', and 'goodness' were also forms. In his 'Republic', the leaders communed with 'the Form of the Good' and embodied it completely.
** Two and a half millennia later, UsefulNotes/CarlJung would adopt Plato's ideas for his theory of "archetypes", that every person is hardwired with mythological symbols that manifest in their myths and religions, while another Carl - [[Creator/CarlSagan Sagan]] - would savage Plato for the rise of religious dogma, by championing the supremacy of the mind over the science of the 'corrupt' natural world.
* This trope is one of the main reasons why many people (often Sci-Fi writers) believe that [[HitlersTimeTravelExemptionAct going back in time to kill Hitler wouldn't prevent the Holocaust or World War 2]]; once his sick ideas were planted in the minds of the Nazis, someone else (perhaps even crazier -- or worse, more [[GeneralFailure competent]] -- than he was) would have continued his work if he was assassinated. Also, even if Hitler didn't come into power and lead the Nazi Party, anti-Semitism, ableism, homophobia, etc. existed (and still continue to exist) centuries before he was born. It wouldn't be a stretch to assume that if Hitler didn't stir up the prejuduces of the 1930s German public in order to get political support, someone else would have done so.
* Speaking of Nazis, people who oppose anti-hate speech laws and other policies aimed at directly suppressing hate groups cite this trope as one of the reasons why they believe they would be ineffective. You can throw them in jail or silence them publicly, but people won't stop being racist simply because someone tells them they can't be.
* This trope is the reason behind {{Thoughtcrime}} policies: because an idea resides in the mind of the individual, it can only be quelled if they themselves suppress it.
* Some minority rights movements have adopted the phrase "rest in power" to indicate that the death of a persecuted individual can empower others to keep fighting persecution.
* Domingo Faustino Sarmiento escaped from Argentina to Chile, during the dictatorship of Juan Manuel de Rosas. Before leaving, he wrote "Barbarians, ideas can not be killed" in a big rock. He worked against Rosas during his exile, and became president of Argentina years later, when Rosas had long been defeated and gone.