Logical Fallacies and the Art of Debate (2024)

Contents:
  • Introduction
  • Sowhy learn logical fallacies at all?
  • Logicas a form of rhetoric
  • Committingyour very own logical fallacies
  • Thelist of fallacies:
    • argumentumad antiquitatem
    • argumentumad hominem
    • argumentumad ignorantiam
    • argumentumad logicam
    • argumentumad misericordiam
    • argumentumad nauseam
    • argumentumad numerum
    • argumentumad populum
    • argumentumad verecundiam
    • circulusin demonstrando
    • complexquestion
    • dictosimpliciter
    • naturalisticfallacy
    • nature,appeal to
    • nonsequitur
    • petitioprincipii
    • posthoc ergo propter hoc
    • redherring
    • slipperyslope
    • strawman
    • tuquoque

Introduction

This is a guide to using logical fallacies in debate. And when I say "using,"I don't mean just pointing them out when opposing debaters commit them-- I mean deliberately committing them oneself, or finding ways to transformfallacious arguments into perfectly good ones.

Debate is, fortunately or not, an exercise in persuasion, wit, and rhetoric,not just logic. In a debate format that limits each debater's speakingtime, it is simply not reasonable to expect every proposition or conclusionto follow precisely and rigorously from a clear set of premises statedat the outset. Instead, debaters have to bring together various facts,insights, and values that others share or can be persuaded to accept, andthen show that those ideas lead more or less plausibly to a conclusion.Logic is a useful tool in this process, but it is not the only tool --after all, "plausibility" is a fairly subjective matter that does not followstrict logical rules. Ultimately, the judge in a debate round has to decidewhich side's position is more plausible in light of the arguments given-- and the judge is required to pick one of those sides, even if logicalone dictates that "we do not know" is the answer to the question at hand.

Besides, let's be honest: debate is not just about finding truth, it'salso about winning. If you think a fallacious argument can slideby and persuade the judge to vote for you, you're going to make it, right?The trick is not getting caught.

So why learnlogical fallacies at all?

I can think of a couple of good reasons. First, it makes you look smart.If you can not only show that the opposition has made an error in reasoning,but you can give that error a name as well (in Latin!), it shows that youcan think on your feet and that you understand the opposition's argumentpossibly better than they do.

Second, and maybe more importantly, pointing out a logical fallacy isa way of removing an argument from the debate rather than just weakeningit. Much of the time, a debater will respond to an argument by simply statinga counterargument showing why the original argument is not terribly significantin comparison to other concerns, or shouldn't be taken seriously, or whatever.That kind of response is fine, except that the original argument stillremains in the debate, albeit in a less persuasive form, and the oppositionis free to mount a rhetorical offensive saying why it's important afterall. On the other hand, if you can show that the original argument actuallycommits a logical fallacy, you put the opposition in the position of justifyingwhy their original argument should be considered at all. If theycan't come up with a darn good reason, then the argument is actually removedfrom the round.

Logicas a form of rhetoric

Unfortunately, the account I have just given is a bit idealized. Not everyjudge will immediately recognize the importance of the logical fallacyyou've pointed out in your opposition's argument. Even if a logician wouldimmediately accept the accuracy of your point, in a debate round it's thejudge that counts.

It is therefore not enough simply to point out a logical fallacy andmove on; there is an art to pointing out logical fallacies in your opposition'sarguments. Here are a few strategies I've found useful in pointing outlogical fallacies in an effective manner:

  • State the name of the logical fallacy, preferably in both Latin and English,and make sure you use the phrase "logical fallacy." Why? Because it isimportant to impress on everyone that this is no mere counterargument youare making, nor are you just labelling the opposition's viewpoint as "fallacious"for rhetorical effect. Stating the fallacy's Latin name helps, becausesome people just aren't sure something's a fallacy unless Aristotle orsome other authority called it one. Say something like, "The oppositionpoints out that the voters supported X by a wide margin in last year'sreferendum. But this is just the logical fallacy of argumentumad populum, appeal to public opinion!"
  • Tell everybody what the fallacy means and why it is wrong. But be careful-- you have to do this without sounding pedantic. You should state thefallacy's meaning as though you are reiterating what you assume your intelligentjudge already knows. To continue the example above, say, "It doesn't matterhow many people agree with you, that doesn't mean it's necessarily right."There, now you've defined for everyone what's fallacious about argumentumad populum.
  • Give a really obvious example of why the fallacy is incorrect. Preferably,the example should also be an unfavorable analogy for the opposition'sproposal. Thus: "Last century, the majority of people in some states thoughtslavery was acceptable, but that didn't make it so!"
  • Finally, point out why the logical fallacy matters to the debate round."This fallacious argument should be thrown out of the debate. And thatmeans that the opposition's only remaining argument for X is...."

Committingyour very own logical fallacies

In general, of course, it's a good idea to avoid logical fallacies if atall possible, because a good debater will almost always catch you. It isespecially important to avoid obvious logical fallacies like the one above(argumentum ad populum), because they are vulnerable to such powerful(and persuasive) refutations. But sometimes, a logical fallacy -- or atleast an unjustified logical leap -- is unavoidable. And there are sometypes of argument that are listed as logical fallacies in logic textbooks,but that are perfectly acceptable in the context of the rules of debate.The most important guideline for committing such fallacies yourself isto know when you are doing it, and to be prepared to justify yourselflater if the opposition tries to call you down for it. For examples oflogical fallacies that can sometimes be acceptable in the context of debate,see adignorantiam, adlogicam, complexquestion, slipperyslope, strawman, and tuquoque in the list below.

Thelist of logical fallacies

What follows is not a comprehensive list of all the known logical fallacies.Nor is this intended as a rigorous philosophical treatise on logical reasoning.(If that's what you're looking for, you should check out the followingexcellent web resources: TheAtheist Web's logic page, or SanJose University's Mission: Critical page; I owe a debt to these pagesfor reminding me of a number of fallacies I had forgotten about.) WhatI have done is compile a list of fallacies that debaters should be familiarwith -- either for pointing them out in others' arguments or for usingand defending them in one's own.

Argumentum ad antiquitatem(the argument to antiquity or tradition). This is the familiarargument that some policy, behavior, or practice is right or acceptablebecause "it's always been done that way." This is an extremely popularfallacy in debate rounds; for example, "Every great civilization in historyhas provided state subsidies for art and culture!" But that fact does notjustify continuing the policy.

Because an argumentum ad antiquitatem is easily refuted by simplypointing it out, in general it should be avoided. But if you must makesuch an argument -- perhaps because you can't come up with anything better-- you can at least make it marginally more acceptable by providing somereason why tradition should usually be respected. For instance, you mightmake an evolutionary argument to the effect that the prevalence of a particularpractice in existing societies is evidence that societies that failed toadopt it were weeded out by natural selection. This argument is weak, butbetter than the fallacy alone.

Argumentum ad hominem (argumentdirected at the person). This is the error of attacking the characteror motives of a person who has stated an idea, rather than the idea itself.The most obvious example of this fallacy is when one debater maligns thecharacter of another debater (e.g, "The members of the opposition are acouple of fascists!"), but this is actually not that common. A more typicalmanifestation of argumentum ad hominem is attacking a source ofinformation -- for example, responding to a quotation from Richard Nixonon the subject of free trade with China by saying, "We all know Nixon wasa liar and a cheat, so why should we believe anything he says?" Argumentumad hominem also occurs when someone's arguments are discounted merelybecause they stand to benefit from the policy they advocate -- such asBill Gates arguing against antitrust, rich people arguing for lower taxes,white people arguing against affirmative action, minorities arguing foraffirmative action, etc. In all of these cases, the relevant question isnot who makes the argument, but whether the argument is valid.

It is always bad form to use the fallacy of argumentum ad hominem.But there are some cases when it is not really a fallacy, such as whenone needs to evaluate the truth of factual statements (as opposed to linesof argument or statements of value) made by interested parties. If someonehas an incentive to lie about something, then it would be naiveto accept his statements about that subject without question. It is alsopossible to restate many ad hominem arguments so as to redirectthem toward ideas rather than people, such as by replacing "My opponentsare fascists" with "My opponents' arguments are fascist."

Argumentum ad ignorantiam(argument to ignorance). This is the fallacy of assuming somethingis true simply because it hasn't been proven false. For example, someonemight argue that global warming is certainly occurring because nobody hasdemonstrated conclusively that it is not. But failing to prove the globalwarming theory false is not the same as proving it true.

Whether or not an argumentum ad ignorantiam is really fallaciousdepends crucially upon the burden of proof. In an American courtroom, wherethe burden of proof rests with the prosecution, it would be fallaciousfor the prosecution to argue, "The defendant has no alibi, therefore hemust have committed the crime." But it would be perfectly valid for thedefense to argue, "The prosecution has not proven the defendant committedthe crime, therefore you should declare him not guilty." Both statementshave the form of an argumentum ad ignorantiam; the difference isthe burden of proof.

In debate, the proposing team in a debate round is usually (but notalways) assumed to have the burden of proof, which means that if the teamfails to prove the proposition to the satisfaction of the judge, the oppositionwins. In a sense, the opposition team's case is assumed true until provenfalse. But the burden of proof can sometimes be shifted; for example, insome forms of debate, the proposing team can shift the burden of proofto the opposing team by presenting a prima facie case that would,in the absence of refutation, be sufficient to affirm the proposition.Still, the higher burden generally rests with the proposing team, whichmeans that only the opposition is in a position to make an accusation ofargumentum ad ignorantiam with respect to proving the proposition.

Argumentum ad logicam (argumentto logic). This is the fallacy of assuming that something is falsesimply because a proof or argument that someone has offered for it is invalid;this reasoning is fallacious because there may be another proof or argumentthat successfully supports the proposition. This fallacy often appearsin the context of a strawman argument.

This is another case in which the burden of proof determines whetherit is actually a fallacy or not. If a proposing team fails to provide sufficientsupport for its case, the burden of proof dictates they should lose thedebate, even if there exist other arguments (not presented by the proposingteam) that could have supported the case successfully. Moreover, it iscommon practice in debate for judges to give no weight to a point supportedby an argument that has been proven invalid by the other team, even ifthere might be a valid argument the team failed to make that would havesupported the same point; this is because the implicit burden of proofrests with the team that brought up the argument. For further commentaryon burdens of proof, see argumentumad ignorantiam, above.

Argumentum ad misericordiam(argument or appeal to pity). The English translation pretty much saysit all. Example: "Think of all the poor, starving Ethiopian children! Howcould we be so cruel as not to help them?" The problem with such an argumentis that no amount of special pleading can make the impossible possible,the false true, the expensive costless, etc.

It is, of course, perfectly legitimate to point out the severity ofa problem as part of the justification for adopting a proposed solution.The fallacy comes in when other aspects of the proposed solution (suchas whether it is possible, how much it costs, who else might be harmedby adopting the policy) are ignored or responded to only with more impassionedpleas. You should not call your opposition down for committing this fallacyunless they rely on appeals to pity to the exclusion of the other necessaryarguments. It is perfectly acceptable to use appeal to pity in order toargue that the benefits of the proposed policy are greater than they mightat first appear (and hence capable of justifying larger costs).

Argumentum ad nauseam (argumentto the point of disgust; i.e., by repitition). This is the fallacyof trying to prove something by saying it again and again. But no matterhow many times you repeat something, it will not become any more or lesstrue than it was in the first place. Of course, it is not a fallacy tostate the truth again and again; what is fallacious is to expect the repititionalone to substitute for real arguments.

Nonetheless, this is a very popular fallacy in debate, and with goodreason: the more times you say something, the more likely it is that thejudge will remember it. The first thing they'll teach you in any publicspeaking course is that you should "Tell 'em what you're gonna tell 'em,then tell 'em, and then tell 'em what you told 'em." Unfortunately, somedebaters think that's all there is to it, with no substantiation necessary!The appropriate time to mention argumentum ad nauseam in a debateround is when the other team has made some assertion, failed to justifyit, and then stated it again and again. The Latin wording is particularlynice here, since it is evocative of what the opposition's assertions makeyou want to do: retch. "Sir, our opponents tell us drugs are wrong,drugs are wrong, drugs are wrong, again and again and again.But this argumentum ad nauseam can't and won't win this debate forthem, because they've given us no justification for their bald assertions!"

Argumentum ad numerum(argument or appeal to numbers). This fallacy is the attempt to provesomething by showing how many people think that it's true. But no matterhow many people believe something, that doesn't necessarily make it trueor right. Example: "At least 70% of all Americans support restrictionson access to abortions." Well, maybe 70% of Americans are wrong!

This fallacy is very similar to argumentumad populum, the appeal to the people or to popularity. When a distinctionis made between the two, ad populum is construed narrowly to designatean appeal to the opinions of people in the immediate vicinity, perhapsin hope of getting others (such as judges) to jump on the bandwagon, whereasad numerum is used to designate appeals based purely on the numberof people who hold a particular belief. The distinction is a fine one,and in general the terms can be used interchangeably in debate rounds.(I've found that ad populum has better rhetorical effect.)

Argumentum ad populum(argument or appeal to the public). This is the fallacy of trying toprove something by showing that the public agrees with you. For an example,see above.This fallacy is nearly identical to argumentumad numerum, which you should see for more details.

Argumentum ad verecundiam(argument or appeal to authority). This fallacy occurs when someonetries to demonstrate the truth of a proposition by citing some person whoagrees, even though that person may have no expertise in the given area.For instance, some people like to quote Einstein's opinions about politics(he tended to have fairly left-wing views), as though Einstein were a politicalphilosopher rather than a physicist. Of course, it is not a fallacy atall to rely on authorities whose expertise relates to the question at hand,especially with regard to questions of fact that could not easily be answeredby a layman -- for instance, it makes perfect sense to quote Stephen Hawkingon the subject of black holes.

At least in some forms of debate, quoting various sources to supportone's position is not just acceptable but mandatory. In general, thereis nothing wrong with doing so. Even if the person quoted has no particularexpertise in the area, he may have had a particularly eloquent way of sayingsomething that makes for a more persuasive speech. In general, debatersshould be called down for committing argumentum ad verecundiam onlywhen (a) they rely on an unqualified source for information about factswithout other (qualified) sources of verification, or (b) they imply thatsome policy must be right simply because so-and-so thought so.

Circulus in demonstrando(circular argument). Circular argumentation occurs when someoneuses what they are trying to prove as part of the proof of that thing.Here is one of my favorite examples (in pared down form): "Marijuana isillegal in every state in the nation. And we all know that you shouldn'tviolate the law. Since smoking pot is illegal, you shouldn't smoke pot.And since you shouldn't smoke pot, it is the duty of the government tostop people from smoking it, which is why marijuana is illegal!"

Circular arguments appear a lot in debate, but they are not always soeasy to spot as the example above. They are always illegitimate, though,and pointing them out in a debate round looks really good if you can doit. The best strategy for pointing out a circular argument is to make sureyou can state clearly the proposition being proven, and then pinpoint wherethat proposition appears in the proof. A good summing up statement is,"In other words, they are trying to tell us that X is true because X istrue! But they have yet to tell us why it's true."

Complex question. A complex questionis a question that implicitly assumes something to be true by its construction,such as "Have you stopped beating your wife?" A question like this is fallaciousonly if the thing presumed true (in this case, that you beat your wife)has not been established.

Complex questions are a well established and time-honored practice indebate, although they are rarely so bald-faced as the example just given.Complex questions usually appear in cross-examination or points of informationwhen the questioner wants the questionee to inadvertently admit somethingthat she might not admit if asked directly. For instance, one might say,"Inasmuch as the majority of black Americans live in poverty, do you reallythink that self-help within the black community is sufficient to addresstheir problems?" Of course, the introductory clause about the majorityof black Americans living in poverty may not be true (in fact, it is false),but an unwary debater might not think quickly enough to notice that thestowaway statement is questionable. This is a sneaky tactic, but debateis sometimes a sneaky business. You wouldn't want to put a question likethat in your master's thesis, but it might work in a debate. But be careful-- if you try to pull a fast one on someone who is alert enough to catchyou, you'll look stupid. "The assumption behind your question is simplyfalse. The majority of blacks do not live in poverty. Get your factsstraight before you interrupt me again!"

Cum hoc ergo propter hoc(with this, therefore because of this). This is the familiar fallacyof mistaking correlation for causation -- i.e., thinking that because twothings occur simultaneously, one must be a cause of the other. A popularexample of this fallacy is the argument that "President Clinton has greateconomic policies; just look at how well the economy is doing while he'sin office!" The problem here is that two things may happen at the sametime merely by coincidence (e.g., the President may have a negligible effecton the economy, and the real driving force is technological growth), orthe causative link between one thing and another may be lagged in time(e.g., the current economy's health is determined by the actions of previouspresidents), or the two things may be unconnected to each other but relatedto a common cause (e.g., downsizing upset a lot of voters, causing themto elect a new president just before the economy began to benefit fromthe downsizing).

It is always fallacious to suppose that there is a causative link betweentwo things simply because they coexist. But a correlation is usually consideredacceptable supporting evidence for theories that argue for a causativelink between two things. For instance, some economic theories suggest thatsubstantially reducing the federal budget deficit should cause the economyto do better (loosely speaking), so the coincidence of deficit reductionsunder Clinton and the economy's relative health might be taken as evidencein favor of those economic theories. In debate rounds, what this meansis that it is acceptable to demonstrate a correlation between two phenomenonand to say one caused the other if you can also come up with convincingreasons why the correlation is no accident.

Cum hoc ergo propter hoc is very similar to posthoc ergo propter hoc, below. The two terms can be used almost interchangeably,post hoc (as it is affectionately called) being the preferred term.

Dicto simpliciter (spokensimply, i.e., sweeping generalization). This is the fallacy of makinga sweeping statement and expecting it to be true of every specific case-- in other words, stereotyping. Example: "Women are on average not asstrong as men and less able to carry a gun. Therefore women can't pulltheir weight in a military unit." The problem is that the sweeping statementmay be true (on average, women are indeed weaker than men), but it is notnecessarily true for every member of the group in question (there are somewomen who are much stronger than the average).

As the example indicates, dicto simpliciter is fairly commonin debate rounds. Most of the time, it is not necessary to call an opposingdebater down for making this fallacy -- it is enough to point out why thesweeping generalization they have made fails to prove their point. Sinceeverybody knows what a sweeping generalization is, using the Latin in thiscase will usually sound condescending. It is also important to note thatsome generalizations are perfectly valid and apply directly to all individualcases, and therefore do not commit the fallacy of dicto simpliciter(for example, "All human males have a Y chromosome" is, to my knowledge,absolutely correct).

Nature, appeal to. This is thefallacy of assuming that whatever is "natural" or consistent with "nature"(somehow defined) is good, or that whatever conflicts with nature is bad.For example, "Sodomy is unnatural; anal sex is not the evolutionary functionof a penis or an anus. Therefore sodomy is wrong." But aside from the difficultyof defining what "natural" even means, there is no particular reason tosuppose that unnatural and wrong are the same thing. After all, wearingclothes, tilling the soil, and using fire might be considered unnaturalsince no other animals do so, but humans do these things all the time andto great benefit.

The appeal to nature appears occasionally in debate, often in the formof naive environmentalist arguments for preserving pristine wildernessor resources. The argument is very weak and should always be shot down.It can, however, be made stronger by showing why at least in specific cases,there may be a (possibly unspecifiable) benefit to preserving nature asit is. A typical ecological argument along these lines is that human beingsare part of a complex biological system that is highly sensitive to shocks,and therefore it is dangerous for humans to engage in activities that mightdamage the system in ways we cannot predict. Note, however, that this approachno longer appeals to nature itself, but to the value of human survival.

For further comment on this subject, see the naturalisticfallacy.

Naturalistic fallacy. Thisis the fallacy of trying to derive conclusions about what is right or good(that is, about values) from statements of fact alone. This is invalidbecause no matter how many statements of fact you assemble, any logicalinference from them will be another statement of fact, not a statementof value. If you wish to reach conclusions about values, then you mustinclude amongst your assumptions (or axioms, or premises) a statement ofvalue. Once you have an axiomatic statement of value, then you may useit in conjunction with statements of fact to reach value-laden conclusions.

For example, someone might argue that the premise, "This medicine willprevent you from dying" immediately leads to the conclusion, "You shouldtake this medicine." But this reasoning is invalid, because the formerstatement is a statement of fact, while the latter is a statement of value.To reach the conclusion that you ought to take the medicine, you wouldneed at least one more premise: "You ought to try to preserve your lifewhenever possible."

The naturalistic fallacy appears in many forms. Two examples are argumentumad antiquitatem (saying something's right because it's always beendone that way) and the appealto nature (saying something's right because it's natural). In bothof these fallacies, the speaker is trying to reach a conclusion about whatwe ought to do or ought to value based solely on what isthe case. David Hume called this trying to bridge the "is-ought gap," whichis a nice phrase to use in debate rounds where your opponent is committingthe naturalistic fallacy.

One unsettling implication of taking the naturalistic fallacy seriouslyis that, in order to reach any conclusions of value, one must bewilling to posit some initial statement or statements of value that willbe treated as axioms, and which cannot themselves be justified on purelylogical grounds. Fortunately, debate does not restrict itself to purelylogical grounds of argumentation. For example, suppose your opponent hasstated axiomatically that "whatever is natural is good." Inasmuch as thisstatement is an axiom rather than the conclusion of a logical proof, therecan be no purely logical argument against it. But some nonetheless appropriateresponses to such an absolute statement of value include: (a) questioningwhether anyone -- you, your judge, or even your opponent himself -- reallybelieves that "whatever is natural is good"; (b) stating a competing axiomaticvalue statement, like "whatever enhances human life is good," and forcingthe judge to choose between them; and (c) pointing out logical implicationsof the statement "whatever is natural is good" that conflict with our mostbasic intuitions about right and wrong.

Non Sequitur ("It does not follow").This is the simple fallacy of stating, as a conclusion, something thatdoes not strictly follow from the premises. For example, "Racism is wrong.Therefore, we need affirmative action." Obviously, there is at least onemissing step in this argument, because the wrongness of racism does notimply a need for affirmative action without some additional support (suchas, "Racism is common," "Affirmative action would reduce racism," "Thereare no superior alternatives to affirmative action," etc.).

Not surprisingly, debate rounds are rife with non sequitur. Butthat is partly just a result of having to work within the time constraintsof a debate round, and partly a result of using good strategy. A debateteam arguing for affirmative action would be foolish to say in their firstspeech, "We also believe that affirmative action does not lead to a racistbacklash," because doing so might give the other side a hint about a goodargument to make. A better strategy (usually) is to wait for the otherteam to bring up an argument, and then refute it; that way, youdon't end up wasting your time by refuting arguments that the oppositionhas never made in the first place. (This strategy is not always preferable,though, because some counterarguments are so obvious and important thatit makes sense to address them early and nip them in the bud.)

For these reasons, it is generally bad form to scream "non sequitur"just because your opposition has failed to anticipate every counterargumentyou might make. The best time to point out a non sequitur is whenyour opposition is trying to construct a chain of causation (A leads toB leads to C, etc.) without justifying each step in the chain. For eachstep in the chain they fail to justify, point out the non sequitur,so that it is obvious by the end that the alleged chain of causation istenuous and implausible.

Petitio principii (beggingthe question). This is the fallacy of assuming, when trying to provesomething, what it is that you are trying prove. For all practical purposes,this fallacy is indistinguishable from circularargumentation.

The main thing to remember about this fallacy is that the term "beggingthe question" has a very specific meaning. It is common to hear debaterssaying things like, "They say pornography should be legal because it isa form of free expression. But this begs the question of what free expressionmeans." This is a misuse of terminology. Something may inspire ormotivate us to ask a particular question without beggingthe question. A question has been begged only if the question has beenasked before in the same discussion, and then a conclusion is reached ona related matter without the question having been answered. If somebodysaid, "The fact that we believe pornography should be legal means thatit is a valid form of free expression. And since it's free expression,it shouldn't be banned," that would be begging the question.

Post hoc ergo propterhoc (after this, therefore because of this). This is the fallacyof assuming that A caused B simply because A happened prior to B. A favoriteexample: "Most rapists read pornography when they were teenagers; obviously,pornography causes violence toward women." The conclusion is invalid, becausethere can be a correlation between two phenomena without one causing theother. Often, this is because both phenomena may be linked to the samecause. In the example given, it is possible that some psychological factor-- say, a frustrated sex drive -- might cause both a tendency toward sexualviolence and a desire for pornographic material, in which case the pornographywould not be the true cause of the violence.

Post hoc ergo propter hoc is nearly identical to cumhoc ergo propter hoc, which you should see for further details.

Red herring. This means exactly whatyou think it means: introducing irrelevant facts or arguments to distractfrom the question at hand. For example, "The opposition claims that welfaredependency leads to higher crime rates -- but how are poor people supposedto keep a roof over their heads without our help?" It is perfectly validto ask this question as part of the broader debate, but to pose it as aresponse to the argument about welfare leading to crime is fallacious.(There is also an element of admisericordiam in this example.)

It is not fallacious, however, to argue that benefits of one kind mayjustify incurring costs of another kind. In the example given, concernabout providing shelter for the poor would not refute concerns about crime,but one could plausibly argue that a somewhat higher level of crime isa justifiable price given the need to alleviate poverty. This is a debatablepoint of view, but it is no longer a fallacious one.

The term red herring is sometimes used loosely to refer to any kindof diversionary tactic, such as presenting relatively unimportant argumentsthat will use up the other debaters' speaking time and distract them frommore important issues. This kind of a red herring is a wonderful strategicmaneuver with which every debater should be familiar.

Slippery slope. A slippery slopeargument is not always a fallacy. A slippery slope fallacy is anargument that says adopting one policy or taking one action will lead toa series of other policies or actions also being taken, without showinga causal connection between the advocated policy and the consequent policies.A popular example of the slippery slope fallacy is, "If we legalize marijuana,the next thing you know we'll legalize heroin, LSD, and crack cocaine."This slippery slope is a form of non sequitur,because no reason has been provided for why legalization of one thing leadsto legalization of another. Tobacco and alcohol are currently legal, andyet other drugs have somehow remained illegal.

There are a variety of ways to turn a slippery slope fallacy into avalid (or at least plausible) argument. All you need to do is provide somereason why the adoption of one policy will lead to the adoptionof another. For example, you could argue that legalizing marijuana wouldcause more people to consider the use of mind-altering drugs acceptable,and those people will support more permissive drug policies across theboard. An alternative to the slippery slope argument is simply to pointout that the principles espoused by your opposition imply the acceptabilityof certain other policies, so if we don't like those other policies, weshould question whether we really buy those principles. For instance, ifthe proposing team argued for legalizing marijuana by saying, "individualsshould be able to do whatever they want with their own bodies," the oppositioncould point out that that principle would also justify legalizing a varietyof other drugs -- so if we don't support legalizing other drugs, then maybewe don't really believe in that principle.

Straw man. This is the fallacy of refutinga caricatured or extreme version of somebody's argument, rather than theactual argument they've made. Often this fallacy involves putting wordsinto somebody's mouth by saying they've made arguments they haven't actuallymade, in which case the straw man argument is a veiled version of argumentumad logicam. One example of a straw man argument would be to say,"Mr. Jones thinks that capitalism is good because everybody earns whateverwealth they have, but this is clearly false because many people just inherittheir fortunes," when in fact Mr. Jones had not made the "earnings" argumentand had instead argued, say, that capitalism gives most people an incentiveto work and save. The fact that some arguments made for a policy are wrongdoes not imply that the policy itself is wrong.

In debate, strategic use of a straw man can be very effective. A carefullyconstructed straw man can sometimes entice an unsuspecting opponent intodefending a silly argument that he would not have tried to defend otherwise.But this strategy only works if the straw man is not too differentfrom the arguments your opponent has actually made, because a really outrageousstraw man will be recognized as just that. The best straw man is not, infact, a fallacy at all, but simply a logical extension or amplificationof an argument your opponent has made.

Tu quoque ("you too"). This isthe fallacy of defending an error in one's reasoning by pointing out thatone's opponent has made the same error. An error is still an error, regardlessof how many people make it. For example, "They accuse us of making unjustifiedassertions. But they asserted a lot of things, too!"

Although clearly fallacious, tu quoque arguments play an importantrole in debate because they may help establish who has done a better jobof debating (setting aside the issue of whether the proposition is trueor not). If both teams have engaged in adhominem attacks, or both teams have made a few appealsto pity, then it would hardly be fair to penalize one team for it butnot the other. In addition, it is not fallacious at all to point out thatcertain advantages or disadvantages may apply equally to both positionspresented in a debate, and therefore they cannot provide a reason for favoringone position over the other (such disadvantages are referred to as "non-unique").In general, using tu quoque statements is a good way to assure thatjudges make decisions based only on factors that distinguish between thetwo sides.

This page has now been translated into Belurussian! You can find the translated version here.

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This page was last modified on 29 January 2001.

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Name: Kelle Weber

Birthday: 2000-08-05

Address: 6796 Juan Square, Markfort, MN 58988

Phone: +8215934114615

Job: Hospitality Director

Hobby: tabletop games, Foreign language learning, Leather crafting, Horseback riding, Swimming, Knapping, Handball

Introduction: My name is Kelle Weber, I am a magnificent, enchanting, fair, joyous, light, determined, joyous person who loves writing and wants to share my knowledge and understanding with you.