Logic and Reasonable Argument
Posted: Tue Dec 27, 2005 4:27 am
[center]Logic and Reasonable Argument[/center]
There is a lot of debate over one issue or the other on these boards. And that's a good thing. One learns from argument. Unfortunately, much of the argument in these forums is of lower quality. Much of it is illogical of nature. The purpose of this thread is to explain some the basics of logical reasoning as I understand them in the hope to improve the overall quality of debate on these boards. I have no special training in philosophy per se save for a minor I took at a university in undergraduate studies when I got out of the Army, so feel free to pitch in with criticism and so forth. This is meant to be a group discussion, not a lecture.
What Is Logic?
One simple definition of logic is given by Webster's Third: the science of correct reasoning. There are many other definitions, but at bottom logic is an intellectual tool which allows a person to analyze an argument, or a string of reasoned points, and work out whether the conclusion is likely to be correct or not. One doesn't need to know a lot about logic to argue, but even a little bit of knowledge in this area will allow you to more readily spot invalid arguments as and when these arise.
What Logic Is Not
In the first place, logic is not some absolute law which governs the known universe. There are countless instances from the past where notable, reasoning men have concluded that because some things were considered to be logically impossible (according to science of the day) then they must be impossible in a practical sense as well. An example of this kind of mistaken assumption would be man's assessment that as only birds had wings, then only birds could fly. Once it was believed that the earth was flat, therefore it was illogical to assume one might "sail around it," though it was perfectly logical to assume that if one sailed too close to the earth's "edge" then one would certainly "fall off." At one time is was held that Euclidean geometry was, in fact, a universal law; now man knows that the rules of Euclidean geometry are not universal. And so it has gone over time. As man's knowledge has increased, so have our logical wayposts changed and shifted to allow us to better rationalize our proper function in relation to, and our actual position within, the universe.
Also, logic should not be construed as some set of ironclad rules which govern human behavior. Humans often entertain logically-conflicting goals and aspirations. For example: Peter needs to speak to whomever is in charge: the person in charge is Paul: therefore Peter needs to speak to Steve. That would be a logical statement, yet it might not be applicable to Peter in the real world. Peter might have a terrible aversion to speaking with Paul which would render such any such conversation a likely disaster. And so, while logic is a powerful tool, it is not the only tool. And while this thread will try to explain how to use logic beneficially, people must decide for themselves whether or not logic is the right tool for their particular job. There are other ways to communicate, discuss and debate.
[center]Fallacies and Fallacious Reasoning[/center]
"Fallacy" and "fallacious" must be two of the most misused words in the English language. Describing something as a fallacy, or stating that a statement is fallacious, is usually interpreted to mean that the statement in question is wrong. But this is not necessarily so.
A fallacy is, generally speaking, an error in reasoning. This differs from a factual error, which is simply being wrong about facts. It's possible, though not likely, for a statement to be fallacious yet still be accurate. In short, an argument could reach the right conclusion through means of a flawed reasoning process.
In short, a fallacy is an "argument" in which the premises given for the conclusion do not provide the needed degree of support for that conclusion. Much of advertising is fallacious of nature. Trying to spot the fallacious reasoning in ads is a fun way to learn to recognize the various types of fallacies.
"Obviously"
As for the use of the word "obviously" in arguments (overemployment of this word is found everywhere), what might be claimed as "obvious" by one person frequently is nothing of the kind to another. Examples of this misuse that occur frequently would include, "Obviously, restricting gun ownership will reduce shooting deaths," "Obviously, we all agree that too many innocent people get executed," and so forth. In cases of these kinds "obviously" is used as a kind of debate club to bully the other party into agreeing with the proposition by means of implication that if they cannot somehow comprehend this "obvious" thing then it must be for the reason they are simply too stupid to understand an otherwise simple relationship or concept. So, as the intent goes, they will agree with the alleged "obvious" thing rather than to look the fool. The catch is that the "obvious" relationships claimed may not be correct in fact or in any logical sense, and may be much less direct than they seem. Indeed, these relationships might be incorrect and without logical ties. On the other hand, an "obvious" relationship may be such a thing to a person who is intimately familiar with a given subject area, but might not be as "obvious" to somebody outside that area.
An example of two "obvious" statements that seem to be contradictory.
"Obviously, it's easy to hit a target coming in on a known trajectory from a known location to a known target at a known time and known speed."
"Obviously, it's extremely hard to hit a bullet with a bullet."
Both statements are "obviously" correct, yet a listener should challenge both and ask for the "obvious" to be explained. Why is it so easy in one case and so difficult in the other? And why are these statements contradictory? Well, ask yourself, "What's missing?"
The answer might be that in the first case someone refers to a guided weapons system, whereas in the second case the reference is to an unguided weapons system.
Anyway, let's look at some common fallacies.
[center]The Ad Hominem Fallacies[/center]
We'll start off with ad hominem fallacies since these are not just numerous and often employed, but can be offensive of nature and so immediately and extremely detrimental to civil discourse.
The ad hominem fallacies are not only commonly employed but also commonly misunderstood. Many people falsely assume that any personal attack or extreme criticism is ad hominem in nature, but this is not true. Some attacks aren't ad hominem fallacies, and some ad hominem fallacies do not necessarily result in obvious insults. In general, there are five separate cases of the ad hominem plea: the Abusive ad hominem, the tu quoque, the Circumstantial ad hominem, the Genetic Fallacy, and Smear Tactics.
Ad hominem is a general category of fallacy in which a claim or argument is rejected on the basis of some irrelevant fact, or implied fact, about the author of an argument or a claim. This kind of fallacy often involves two basic building blocks of bad argument: the first building block presents itself in the form of an attack against the character of the person making his argument or some claim, or perhaps the attack will be against the individual's circumstances, or it could even be launched against his actions; the second building block is presented as "evidence" against the argument or claim in question.
Ad hominem arguments or pleas of any kind are fallacious for the reason that a person's character, or a person's circumstances, or even his actions, do not necessarily bear on the truth or falsity of his argument or claim.
Abusive ad hominem
In formal case the abusive ad hominem plea might play out thusly: person A makes argument X: then person B attacks person A: with person A now discredited to whatever extent, his argument is hoped to be judged false.
Let's make up a conversational example of a typical Abusive ad hominem plea at work.
Suppose Tom says, "I believe the death penalty is morally wrong for this reason, that reason and the other reason." Larry responds, "You only say that because you're a priest!" Tom might then respond, "But what about the reasons I gave in support of my position?" Larry: "Those don't count. As I've already pointed out, you're nothing but a crazy Catholic, plus everyone knows priests abuse children, so nobody could believe anything they said!"
Current simplistic attacks on President Bush from various mainstream media outlets serve as excellent examples of ad hominem pleas to the masses. It's an old technique of "discredit the man" in order to discredit the man's ideas and work. A simple form of this is all too often encountered along the lines of, "President Bush is not articulate in his speech, on top of that he wears cowboy boots, and therefore nothing he says could have credence. And that is why our troops should not be in Iraq."
Again, suppose an author wrote a book which served to dispel the notion that Houdini was able to converse with spirits. A typical attack would be, "Of course you'd say that, but you're a dirty atheist so who could believe you? " And so on.
Tu Quoque
A special form of ad hominem plea, tu quoque (from the Latin, "you, also" or "you're another") is a fallacious argument which concludes that a person's claim is false because 1) it is inconsistent with something else a person has said or 2) what a person says is inconsistent with his actions.
Now the fact that a person makes inconsistent claims does not make any particular claim he makes false (although of any pair of inconsistent claims, only one can possibly be true, though both could be false). The fact that a person's claims are not consistent with his actions might indicate that the person is a hypocrite, say, but this does not prove his claims to necessarily be false.
For example, when accused of rigging the polls in Florida during the 2000 national election, some Democrats responded, "Well, the Republicans have rigged elections as well." This would be a perfect example of the ad hominem tu quoque argument.
In this case of ad hominem plea, instead of attacking the original person who makes an argument on grounds unrelated to the argument itself, the attacker aims to discredit the argument for some perceived fault of the person instead.
In the classic "fight fire with fire" rationalization a man might claim, "I'm justified in attacking you because you attacked me earlier!" Or, "How can you insist it's wrong to drink and drive when you yourself have been cited for DUI?" The justification here is that an action is somehow proper because someone else has already behaved likewise. But the fallacy is that just for the reason that person A is hypocritical in some sense does not constitute evidence that person A's argument or claim is without merit.
It's a small step from "if you did something then so can I" to supposing "you would do something if you had the chance." In this manner we find arguments constructed such as: "Those people are utterly ruthless in their business practices, so we should screw them first if we get the chance." This is bad reasoning as it doesn't matter (logically speaking) what someone else might do if capable. That realization in and of itself constitutes no good argument that the action in question is right, correct or even moral.
More subtly, this plea might be presented in the form: "You argue that it is wrong to take a man's life, yet you work in as a guard in a prison in a state with capital punishment, and you have personally pulled the switch, therefore why should I accept a belief which you obviously don't believe in very strongly yourself?"
The reasoning here is that if person A acts in some manner which seems to contradict his claim, or seems to suggest that person A does not actually strongly believe in the underlying tenets of his position, then that claim or position must be false. But just because someone acts inconsistently in his own life does not constitute evidence that a claim he makes is false, or that a position he maintains has no intrinsic merit.
That doesn't mean we cannot point out glaring inconsistencies when these are presented in arguments. These inconsistencies might indicate that a person does not believe what he espouses, in which case it would be legitimate to ask why then should anyone else believe in this thing? It might also be the case that a person simply misunderstands his own argument, in which case it could turn out that no effective defense for the argument can be found.
Circumstantial ad hominem
In this case an effort is made to dismiss an argument through means of an attack on a person or an entire class of people who believe something to be true. In formal presentation this argument runs: it is not surprising to discover that person/people A believes/believe X is a good thing: the reason for this belief is found in the circumstances of person/people A.
Conversationally this argument might well run in today's mainstream press: "President Bush and his family have long been known to possess ties to oil interests, therefore his call for more off-shore exploration and drilling to offset America's oil dependence on Saudi Arabia must be selfishly motivated and thus bad for this country."
In this example the pros and cons of the issue of "off-shore exploration and drilling" are not directly addressed, only the suggestion that the man who has suggested this action probably has selfish motives.
Again: "The Green Bay Packers couldn't possibly be as bad as their 3-12 record indicates. They are taking games this season in order to get the #1 draft choice and have the rights to Reggie Bush." The suggestion is that because of Green Bay's supposed motive to move up in the NFL draft the team is not trying to win, whereas in fact no sound argument has been made to support this argument, only that the "circumstances" surrounding the team's poor performances seem suspicious.
Finally: "Why should we believe anything President Bush says? He lied to us about weapons of mass destruction, so how could we believe him or anyone else in the war or state departments when claims are made that the war in Iraq is going better than planned?"
This is a sort of combination of abusive and circumstantial ad hominem, with a strong dose of innuendo thrown in for good measure
The argument first calls the president a liar (who would believe a liar, after all?) when in fact no evidence has been presented that he is in fact a liar (perhaps he was merely mistaken or confused or lied to himself--a significant difference), then by association everyone in the war and state departments are lumped together with the president as being somehow untrustworthy, too, with the overall implication being that anything any of them says with regard to the war in Iraq going well must be false, ergo the war in Iraq is not going well but is, in fact, a failure.
Nothing could be more illogical than to make that kind of argument, yet we find it all the time, and not just in casual debates on forums runs by recreational software companies like Matrix, but in professionally-written articles in magazines, major daily newspapers and in mainstream news broadcasts.
The Genetic Fallacy
This fallacious variation of ad hominem doesn't attack the person but rather wants to erode the base, root or origin of an argument. The "logic" in this instance assumes that because an idea comes from a bad place then that idea must itself be bad.
To wit: "The World Health Organization has in the past been closely associated with Fidel Castro and Cuba. Castro is a known tyrant, and Cuba is not a nation of free people. Therefore no one who has respect for human rights should have anything to do with WHO or respect its work it."
Here it is concluded illogically that the WHO is a dubious organization based on its association with the leader of a brutalized nation. The link here is "genetic" because it's based on the false assumption that just because the source of some of WHO's assistance derives from an unhealthy place, then the organization itself and the work it does must be correspondingly unhealthy.
Smear Tactics
This is the "preemptive strike" of ad hominem pleas. Smear tactics aim to discredit a person before he has a chance to make an argument through the presentation of unfavorable information (true or false, it makes no difference) about him. The argument usually runs like this: person A is a bad apple: therefore anything he say today, tomorrow, or the day after tomorrow ought to be dismissed out of hand.
This form of argument, also known as "poisoning the well," the etymology of which dates back to medieval Europe where Christians widely held that Jews had brought plague to the land by poisoning the wells with it (ironically, this same "logical" principle can be traced back to Rome, where Christians themselves were blamed for all sorts of bad things, and duly persecuted because of this), can be both abusive and circumstantial in nature.
For instance:
"He's a fool!"
is an abusive form, whereas,
"He says that's good because he hawks it for his living."
would be a kind of circumstantial plea at work.
As with all other forms of ad hominem pleas, a person who debates under such circumstances is likely to find himself under personal assault, or at the least debating something other than the original idea tendered for examination.
In fact, smear tactics are not actually arguments at all, but rather unhandsome window dressing which sets the stage for the audience to fall into some other fallacious trap. To avoid this and similar pitfalls, always keep in mind that arguments must either stand or fall on their own merits.
There are many other kinds of fallacies. Almost without number. Let's examine some of these.
The Fallacy of Composition
This fallacy comes in two forms which are similar. This reasoning argues wrongly from a premise where a term is employed distributively to a conclusion in which it is used collectively. It is falsely assumed that what is true of a whole must also be true of all the whole's parts.
The first fallacy-of-composition type arises when a person reasons from the characteristics of individual members of a class or group to a conclusion regarding the characteristics of the entire class or group (taken as a whole). Formally, this argument runs: individual X things have the characteristics of A, B, C: therefore, the entire class of X has the characteristics of A, B, C.
This line of reasoning is clearly bad. The mere fact that an individual might have certain characteristics does not guarantee that everyone has those characteristics. However, drawing an inference about the characteristics of a class based on the characteristics of its individual members is not always fallacious. In a given case sufficient justification might be provided to warrant the conclusion, but this justification must be demonstrated, not assumed.
The second type of fallacy of composition is committed when it is concluded that what is true of the parts of a whole must be true of the whole itself without the justification for this conclusion demonstrated. Formally: parts of the whole X have characteristics A, B, C: therefore the whole X must have characteristics A, B, C.
It cannot be reasonably inferred that simply because parts of a complex whole have (or for that matter lack) certain properties, that the whole they are constituents of has (or lacks) those properties. In a mathematical sense this argument might run: the numbers 1 and 3 are both odd: 1 and 3 are parts of 4: therefore the number 4 is an odd number.
This reasoning, too, is not always fallacious. If there is justification for the inference from parts to the whole, then the reasoning is sound. Example: if all parts of a structure were composed of glass, no fallacy is committed to conclude the entire structure is composed of glass.
Examples of bad reasoning along this line would include, "As a horse eats more food than a human being, therefore horses as a group eat more food than do all the humans on the planet," and "As atoms are without color, and cats are made of atoms, cats are colorless, too."
Finally, "As every player on the team is a superstar, the team is a great team." This would be fallacious since it has not been demonstrated that these superstars are able to play together effectively. Hence, the team might be lousy even though all the players are talented. It would be like telling someone, "Look, you like pizza and beer, and ice cream and soda, therefore you're going to love this shake I made of pizza, beer, ice cream and soda."
Turn this "logic" around and we have the Fallacy of Division, where it is errantly reasoned that one might find truth in the collective sense and then apply that to the parts of the argument when used distributively. That is, that what is true for a whole must be true for the constituents of that whole. Example: "The number 4 is an even number. As 1 and 3 are both parts of 4, therefore 1 and 3 are even numbers."
Anyway, there is no end to man's ability to "reason" fallaciously. For example, we have both the fallacy of Denying the Antecedent and Affirming the Consequent. Examples of denying the antecedent can be found in the following constructs:
"If I go outside and run too hard I will have a heart attack and die. As I never go outside and run at all I'll never die of a heart attack."
or
"Sex, booze and women all shorten lives. Therefore I shall give up sex, booze and women, take up the cinema instead, and live forever."
In both cases, our thinker might well have then gotten into his car, headed for the cinema, and suffered a fatal heart attack in the front row. The problem with this kind of "reasoning" is that it fails to see that different actions might cause similar events.
As it is with denying the antecedent, affirming the consequent is a line of reasoning perfectly suited for those who proceed through life like Mr. Magoo, and is especially for those favorably disposed toward conditional arguments. A formal example would run: action A results in X result: result X is before me, therefore action A must have occurred.
In real life we might find, "The wife must have killed her husband for the insurance, as she had just taken out a large life insurance policy on him." Given the many alternative possibilities, that would represent a kind of "Lestradian" deduction.
In these kinds of if-then constructs, it is all right to affirm to antecedent (if) in order to prove the consequence (then), but the opposite does not hold true. So, if one were to say: "If a man falls out of the sky from 10,000 feet he will die; that man fell 10,000 feet out of the sky and so he died" would be an acceptable, common sort of argument, or modus ponens. It would not be acceptable to suggest, "If a man falls out of the sky from 10,000 feet he will die; this man is dead therefore he fell 10,000 feet out of the sky." Clearly, in the second case the man we find dead might have died of many causes other than falling out of the sky from a great height.
The Appeal to Authority
This is also known as "Fallacious Appeal to Authority," "Misuse of Authority," "Irrelevant Authority," "Questionable Authority," "Inappropriate Authority" and ad verecundiam. These forms are fallacious when the person in question is not, in fact, an expert in the given area under scrutiny, but merely an "expert" in some other guise. In such cases the argument is flawed because the fact that an unqualified person makes a claim does not provide any justification for the claim. The claim could be true, but the fact that an unqualified person made the claim does not provide any rational reason to accept the claim as true.
When a person falls prey to this fallacy, they accept a claim to be true absent adequate evidence. The person accepts the claim because he erroneously believes the person making the claim is a legitimate expert, hence by extension the claim is reasonable to accept. Since people have a tendency to believe authorities (and there are good reasons to accept some claims made by some authorities in some cases) this fallacy is very common. Since this argument is fallacious only when the authority figure referenced is not a legitimate authority in a particular context, it is necessary to provide acceptable standards of assessment. The following standards can be accepted:
•The authority figure has sufficient expertise in the subject matter in question
•The claim made by the authority is within his area(s) of expertise
•There is adequate degree of agreement among other experts in the field with regard to the subject in question
•The authority in question is not significantly biased
•The area of expertise is a legitimate area or discipline of accredited study
•The authority in question must be identified
(This last standard is often abused and almost constitutes a fallacious subargument known as The Appeal to an Unnamed Authority. Typically, the person making this kind of argument will say things like "I have a book that says...", or "they say...", or "the experts say...", or "scientists believe that...", or "I read in the paper..." or "I saw on TV..." or some similar statement. In such cases the speaker hopes the listener(s) will simply accept the unidentified source as a legitimate authority and believe the claim made. If an audience accepts this claim simply because it accepts the unidentified source as an expert--without good reason to do so--it has fallen prey to this fallacy.)
Not all appeals to authority are fallacious; people often have to rely on experts because no one person can be an expert on everything, and people do not have the time or ability to investigate every single claim themselves. To distinguish a valid argument from a fallacious appeal to authority, the argument must meet the six standards noted above. However, even a valid appeal to authority is not an exceptionally strong argument. After all, in such cases a claim is accepted as true simply because a person asserts it is true. The authority in question may be an expert, but it could be his expertise does not bear specifically on the truth of that particular claim (the expertise of an authority does not actually determine whether the claim is true or false--that hinges case by case). Hence, arguments that deal directly with evidence relating to the claim itself will be stronger, with perhaps the (valid) appeal to authority used as an addendum and brace for that.
The Appeal to Belief
An appeal to belief is fallacious because the fact that many people believe a claim does not, in general, serve as evidence that the claim is true. There are, however, some cases when the fact that many people accept a claim as true is an indication that it is true. For example, while you are visiting Maine, you are told by several people that they believe people older than 16 need to buy a fishing license in order to fish. Barring reasons to doubt these people, their statements give you cause to believe that anyone over 16 will need to buy a fishing license.
There are also cases in which what people believe actually determines the truth of a claim. For example, the truth of claims about manners and proper behavior might simply depend on what people believe to be good manners and proper behavior. Another example is the case of community standards, which are often taken to be the standards that most people accept. In some cases, what violates certain community standards is taken to be obscene. In such cases, for the claim "x is obscene" to be true then most people in that community would need to believe that x is obscene. In such cases it is still prudent to question the justification of the individual beliefs.
The Appeal to Common Practice
This is a fallacy because the mere fact that most people do something does not make it correct, moral, justified, or reasonable.
However, an appeal to fair play, which might seem to be an appeal to common practice, need not be a fallacy. For example, a woman working in an office might say, "The men who do the same job as I do get paid more than I get paid, therefore it would be fair for me to get paid the same as them." This would not be a fallacy as long as there was no relevant difference between her and the men (in terms of ability, experience, hours worked, etc.).
This kind of argument rests heavily on the principle of relevant difference. According to this principle, two people, Smith and Jones, can only be treated differently if and only if there is a relevant difference between them. For example, it would be fine for me to give a higher salary to Smith than Jones if Smith did better work than Jones. However, it would be wrong of me to give Smith more money than Jones simply because Smith has red hair and Jones has brown hair.
There might be some cases in which the fact that most people accept X as moral entails that X is moral. For example, one view of morality is that morality is relative to the practices of a culture, time, person, etc. If what is moral is determined by what is commonly practiced, then this argument would not be a fallacy.
This might, however, lead to odd results. For example, imagine that there are 100 people who live in a community, 60 of which do not cheat and steal, while 40 do. At this time, cheating and stealing would be wrong. The next day, a natural disaster kills 30 of the 60 people who did not cheat or steal. Now it is morally correct to cheat and steal. Thus, it would be possible to change the moral order of any communal context to one's view simply by eliminating those who disagree.
The Appeal to Consequences of a Belief
This line of "reasoning" is fallacious because the consequences of a belief have no bearing on whether the belief is true or false. For example, if someone were to say, "If pink elephants didn't exist then I would be miserable, so they must exist as I am happy with my lot," this would not be a valid line of reasoning. It is important to note here that the consequence in question stems directly from this man's belief that he could not possibly be happy unless these pleasing elephants existed, a kind of preposterous test.
We must learn to distinguish between a rational reason to believe (RRB, which is supported by evidence) and a prudential reason to believe (PRB, a reason spurned by motivation). An RRB connotes evidence that objectively and logically supports the position, whereas a PRB comes saddled with a dubious belief due to some external factor (fear, a threat, a benefit or harm that may stem from belief, hope, a wish) that is relevant to what a person values but is not relevant to the truth or falsity of the position.
The nature of this fallacy seems especially clear in the case of Wishful Thinking, which is also referred to as "positive thinking," "optimism," "visualization," and just plain "faith." In this argument the premise defines a desire for something to be true. The problem with this line of "reasoning," as attractive as it must seem to many people, is that merely wishing something to be true does not make it true. Just because one wishes that the mortgage were paid does not actually make that mortgage paid. And if you don't believe me, just ask the mortgage holder!
This is, perhaps, the most difficult of all fallacies to overcome, as we all have an inbuilt tendency to see the world the way we want to see it, through rose-colored glasses as it were, rather than the way it actually appears. We all at times wish only to hear what we wish to hear, see only what we wish to see, read meaning where no meaning exists, and pretty much just pleasantly daydream a new existence. But as therapeutic as that may or may not be psychologically speaking, it is not a good method to practice in debate, where it will inevitably lead to one unsound conclusion after the next.
One might term a conclusion reached through this crippled means as a kind of perceived reality, where cognitive bias leads one into an altered mental state where yes might be no, in might be out, black might be white, and so on and so forth. This is quite "normal" in a manner of speaking and as far as that goes. We are all susceptible to this Walter Mitty phenomenon to one extent or another, and as long as one doesn't travel too far down that road in his regular life he should be okay. But we are asked to buck it up in debate, and ruthlessly beat down this tendency to dream when it rears its ugly head. Should we hope to thoughtfully investigate life and derive valid conclusions from the world around us, there is no other possibility.
The Appeal to Emotion
This fallacy is committed when someone manipulates emotions in order to get the audience to accept a claim as being true. This sort of "reasoning" is extremely common in politics, and it serves as the basis for a large portion of modern advertising. It is fallacious because using tactics to incite emotions in people does not serve as evidence for a claim.
For example, if a person were able to instill in another person an incredible hatred of the claim that 1+1 = 2, then further inspire in that other person a love for the claim that 1+1 = 3, it would hardly follow that the claim that 1+1 = 3, even though the second person fervently believed this to be so.
It should be noted that in many cases it is not obvious that the person committing the fallacy is attempting to support a claim, thus this method assumes an insidious nature and is an extremely effective persuasive device. For example, "Ban guns, they're dangerous to children" might be an extremely effective argument at face value, though upon closer examination it might fail.
A strong argument can be made that emotions carry much more force (or more to the point are easier to manipulate) than a more intellectual approach with many people. Logical argumentation is often difficult and time consuming, and it often lacks the power and sense of urgency to spur people to action. It is the real-world power of emotional appeals that explains their popularity and wide usage. However effective this technique may be, though, it is still fallacious.
It should be noted that the use of tactics to inspire emotions is an important skill to possess. Without an appeal to peoples' emotions it is often difficult, as suggested above, to get them to take action or to perform at their best in critical situations; however, it mustr be stated again that this is not an acceptable form of formal argumentation. In a pinch, use it if you must. In a debate, leave it at home.
In any event, as long as one is able to distinguish between what excites one's emotions and what constitutes a valid claim, one is unlikely to fall prey to this fallacy. But be on your guard always. This method is in use everywhere.
The Appeal to Fear
This line of "reasoning" is fallacious because creating fear in people does not constitute evidence for a claim. It is important to distinguish between a rational reason to believe (RRB, or "evidence") and a prudential reason to believe (PRB, or "motivation"). A RRB is evidence that objectively and logically supports the claim. A PRB is a reason to accept the belief because of some external factor (such as fear, a threat, or a benefit or harm that may stem from the belief) that is relevant to what a person values but is not relevant to the truth or falsity of the claim.
For example, it might be prudent to not fail the son of your department chairman because you fear he will make life tough for you. However, this does not provide evidence for the claim that the son deserves to pass the class. A classic appeal to fear fallacy would be: "You must believe that God exists. After all, if you do not accept the existence of God, then you will face the horrors of hell."
The Appeal to Flattery
The basic idea behind this fallacy is that flattery is presented in the place of evidence for accepting a claim. This is fairly easy to spot: "My, Bill, that is a really nice tie. By the way, it is quite clear that one plus one equals three."
The Appeal to Novelty
Appeal to novelty is a fallacy that occurs when it is assumed that something is better or correct simply because it is new. This sort of "reasoning" is fallacious because the novelty or newness of something does not automatically make it correct or better than something older. This is made quite obvious by the following example: Joe has proposed that 1+1 should now be equal to 3. When asked why people should accept this, he says that he just came up with the idea. Since it is newer than the idea that 1+1=2, it must be better.
This sort of "reasoning" is appealing for many reasons. First, "western culture" includes a very powerful commitment to the notion that new things must be better than old things. Second, the notion of progress (which seems to have come, in part, from the notion of evolution) implies that newer things will be superior to older things. Third, media advertising often sends the message that newer must be better. Because of these three factors (and others) people often accept that a new thing (idea, product, concept, etc.) must be better because it is new. Hence, Novelty is a common fallacy, found especially in advertising.
The Appeal to Pity
An appeal to pity is a fallacy in which a person substitutes a claim intended to create pity for evidence in an argument. This line of "reasoning" is fallacious because pity does not serve as evidence for a claim.
For example: "You must accept that 1+1=3. After all, I lie here dying before you." While you may pity me because I am dying, it would hardly make my claim true.
(This fallacy differs from the "Appeal to the Consequences of a Belief." In this fallacy, a person uses the effects of a belief as a substitute for evidence. There are various forms of this "reasoning." For instance, "A must be so, because if we did not accept A then negative consequences would be the result," or " X must be so because by accepting that truth brings positive consequences." And finally, we find this in the form of "wishful thinking," where "I wish that X were true, therefore X is true.")
In the Appeal to Pity, it is the feelings of pity or sympathy that are substituted for evidence. It must be noted that there are cases in which claims that actually serve as evidence also evoke a feeling of pity. For example, getting run over by a truck would be a legitimate excuse for missing a deadline and might evoke pity for the person run over. Still, in such case the feeling of pity is not evidence.
The Appeal to Popularity
The idea here is that a claim should be accepted as being true simply because most or many people are so favorably inclined. The fact that most or many people have favorable opinions of the claim is substituted in place of actual evidence for the claim. A person falls prey to this fallacy if he accepts a claim as being true simply because many or most other people approve of the claim. It is fallacious to accept the approval of the majority as evidence for any claim.
For example, suppose a skilled speaker managed to get many people to absolutely love the claim that 1+1=3. It would still not be rational to accept this claim simply because many people approved. Wide approval of one's peers in such a case is no substitute for an absolute (mathematical) proof.
At one time people approved of claims such as "the world is flat," "humans cannot survive at speeds greater than 25 miles per hour," "the sun revolves around the earth," but all these claims turned out to be false.
This sort of "reasoning" is quite common and can be a persuasive device. Since many (if not most) people tend to conform with the views of the majority, convincing a person that the majority approves of a claim is often an effective way to get him to accept that claim as truth. Advertisers often use this tactic when they attempt to sell products by claiming that many other people use and love the given products. In such cases the advertisers hope that people will accept the (purported) approval of "many others" as a good "reason" to buy the product themselves.
The Appeal to Ridicule
This is a fallacy in which ridicule or mockery is substituted for evidence in an argument. This sort of "reasoning" is fallacious because mocking a claim does not demonstrate its falsehood.
A simple example would be: "One plus one equals two?! That's the most ridiculous thing I have ever heard!"
It should be noted that demonstrating a claim to be ridiculous through the use of legitimate methods (such as a non-fallacious argument) can make it reasonable to reject the claim. One form of this line of reasoning is known as reductio ad absurdum (reducing to absurdity). In this sort of argument, the idea is to show that a contradiction (a statement that must be false) or an absurd result follows from a claim. One establishes a contention by deriving an absurdity from its denial, thus arguing that a thesis must be accepted because its rejection would be untenable. It is a sound and ancient style of reasoning that has been employed throughout the history of philosophy and mathematics.
For example: "Bill claims that a member of a minority group cannot be a racist. However, this is absurd. Think about this: white males are a minority in the world. Given Bill's claim, it would follow that no white males could be racists. Hence, the Klan, Nazis, and white supremacists are not racist organizations." Since the claim that the Klan, Nazis, and white supremacists are not racist organizations is clearly absurd, it can be concluded that the claim that a member of a minority cannot be a racist is false.
The Spiteful Fallacy
A fallacy in which spite is substituted for evidence when an argument is made against a claim. This sort of "reasoning" is fallacious because a feeling of spite does not count as evidence for or against a claim.
Example: "Bill claims that the earth revolves around the sun. But remember that dirty trick Bill pulled on you last week? Now, doesn't my claim that the sun revolves around the earth make more sense to you?"
Of course, there are cases in which a claim that also evokes feelings of spite or malice can serve as legitimate evidence. However, the feelings of malice or spite are not evidence. So, the statement "Since a city treasurer should be honest, a known thief would be a bad choice for that position" rings true enough, and no doubt will raise bad feelings against known thieves residing in city government, but those bad feelings in and of themselves do not constitute evidence that they would make for bad treasurers.
The Appeal to Tradition
This fallacy occurs when it is assumed that something is better or more correct simply because it is older, more traditional, "has always been done that way." This sort of "reasoning" is fallacious because the age of something does not automatically make it correct or better than something newer.
For example: "The theory that witches and demons cause disease is far older than the theory that microorganisms cause diseases. Therefore, the theory about witches and demons must be true."
This sort of argument can be appealing for any number of reasons. People often prefer to stick with what is older or traditional--this is a fairly common psychological characteristic of people which may stem from the fact that people feel more comfortable about what has been around longer, or simply tend to resist change in general. Also, sticking with things that are older or traditional is easier than to test new things. Hence, people often prefer older and traditional things out of laziness.
Age might well have pertinence in some contexts. If a person concluded that aged wine might well taste better than brand-new wine, he would not be committing an appeal to tradition. This is because in this case we know that the age of a particular wine often proves to be relevant to its quality. Thus, the fallacy is committed only when the age is not in and of itself relevant to the claim.
One final case that should be considered is the Test of Time. People might assume that because something has lasted as a tradition over the years (has been around a long time) that this could only be so because it has "passed the test of time." If a person assumes that something must be correct or true simply because it has persisted a long time, then he has fallen prey to an "Appeal to Tradition." After all, history shows people can indeed persist in accepting false claims for centuries. However, if a person argued that the claim or thing in question had successfully stood up to valid tests for a long period of time, then he would not be committing a fallacy. In such cases the claim would be backed by evidence derived from said tests.
As an example: the theory that matter is made of subatomic particles has survived numerous tests and challenges over the years, and so there is a weight of evidence in favor of this theory. The claim seems reasonable to accept because of the weight of this evidence, not because the claim itself dates back any number of years.
The Bandwagon Fallacy (aka peer pressure)
The "Bandwagon" is a fallacy in which a threat of rejection by one's peers (peer pressure) is substituted for evidence in an argument. This line of "reasoning" is fallacious because peer pressure and threat of rejection do not constitute evidence for rejecting a claim. It should be noted that loyalty to a group and the need to belong can give people very strong reasons to conform to the views and positions of those groups. From a practical standpoint we often compromise our beliefs in order to belong to groups; however, feelings of loyalty and the need to belong do not constitute evidence for a claim.
Begging the Question
Also known as "circular reasoning" or petitio principii, in this fallacy the premise includes the claim that the conclusion is true or (directly or indirectly) assumes the conclusion is true. This sort of "reasoning" is fallacious because simply assuming that the conclusion is true (directly or indirectly) in the premise does not constitute evidence for that conclusion. Simply assuming a claim is true does not serve as evidence for that claim. This is especially clear in particularly blatant cases: "X is true. The evidence for this claim is that X is true." Some cases of question begging are fairly blatant, while others can be subtle.
For instance, a blatant case would be:
"God must exist."
"How do you know that?"
"Because the Bible says this is so."
"Why should I believe what the Bible says?"
"Because the Bible was written by men of God."
A more subtle form: "Sure, this was Indian Territory once, and the white settlers didn't always treat the Indians well, or always live up to treaties. But there is no question we have every right to be here and to enjoy this land. After all, we brought civilization to the Indians, a clearly superior way of life. You'd think they'd be grateful."
Biased Sample
This fallacy is committed when a person draws a conclusion about a population based on a sample that is biased or prejudiced in some manner. The person committing the fallacy is misusing a type of reasoning known variously as "Inductive Generalization" and "Statistical Generalization." The fallacy is committed when the sample is likely to be biased in some manner.
A sample is biased or loaded when the method used to select the sample results in a sample that does not adequately represent the population from which it is drawn. Biased samples are generally not very reliable. The idea is that biased samples are less likely to contain opinion proportional to and thus representative of the whole population. For example, if a person wants to find out what most Americans think about gun control, a poll taken only at an NRA meeting would represent a biased sample. So would a similar poll taken at a meeting of Handguns Control Inc.
Since the Biased-Sample fallacy is committed when the sample is biased or loaded, it is important to have samples that are not biased, or rather more balanced. The best way to achieve this state is to take samples in ways that avoid known bias. There are, in general, three types of samples that are aimed at avoiding bias. These methods (when used properly) will result in a sample that matches the whole population fairly closely. The three types of samples are as follows
Random Sample: This is a sample that is taken in such a way that nothing but chance determines which members of the population are selected for the sample. Ideally, any individual member of the population has the same chance as being selected as any other. This type of sample tends to avoid being biased because a biased sample is one that is taken in such a way that some members of the population have a significantly greater chance of being selected for the sample than other members. Unfortunately, creating an ideal random sample is difficult.
Stratified Sample: This is a sample that is taken by using the following steps: 1) the relevant strata (population subgroups) are identified, 2) the number of members in each stratum is determined and 3) a random sample is taken from each stratum in exact proportion to its size. This method is most useful when dealing with stratified populations. For example, a person's income often influences how he votes, so when conducting a presidential poll it would be a good idea to take a stratified sample using economic classes as the basis for determining the strata. This method avoids loaded samples by (ideally) ensuring that each stratum of the population is adequately represented.
Time-lapse Sample: This type of sample is taken by taking a stratified or random sample and then taking at least one more sample with a significant lapse of time between them. After the two samples are taken, they can be compared for changes. This method of sampling is important when making predictions. A prediction based on only one sample is likely to be a Hasty Generalization (because the sample is likely to be too small to cover past, present and future populations) or a Biased Sample (because the sample will only include instances from one time period).
People often commit biased sampling because of their own bias and prejudice. For example, a person might intentionally or unintentionally seek out people or events that support a given bias of his. So, a person who is pushing a particular scientific theory might tend to gather samples that are biased in favor of that theory. People also commonly commit this fallacy because of laziness or sloppiness. It is easer to simply take a sample from what happens to be available rather than taking the time and effort to generate an adequate sample and draw a justified conclusion. It is important to keep in mind that bias is relative to the purpose of a given sample. What may be a biased sample in one context may not be in another.
Burden of Proof
This fallacy occurs when the burden of proof is placed on the wrong side. Another version occurs when a lack of evidence for side A is taken to be evidence for side B in cases in which the burden of proof actually rests on side B. A common name for this is an Appeal to Ignorance.
In many situations, one side has the burden of proof resting on it. This side is obligated to provide evidence for its position. The claim of the other side, the one that does not bear the burden of proof, is assumed to be true unless proven otherwise. The difficulty in such cases is determining which side, if any, the burden of proof rests on. In many cases, settling this issue can be a matter of significant debate. In some cases the burden of proof is set by the situation.
For example, in American law (except, as far as I know, in Louisiana) a person is assumed to be innocent until proven guilty, hence the burden of proof in law is on the prosecution.
Another example: in formal debate, the burden of proof is placed on the affirmative team. So, one side asserts that Proposition A is a good thing. Therefore, the side that holds Proposition A to be good thing is obliged to demonstrate in fact that it is a good thing. One does not demand that the other side prove Proposition A is not a good thing, though as a matter of practice that side often tries, sometimes successfully, to demonstrate just that--but this effort is voluntary, not obligatory.
In general, the burden of proof rests on those who claim something exists (such as Bigfoot, psychic powers, universals) or the need for something exists (health care, traffic laws, public education). This is for the reason that to prove a positive is easier (if in fact something is positive, it must be logically assumed that there exists evidence of this positive attribute) than to prove a negative (where the case often arises than not all possible scenarios might ever be exhausted, therefore the case could never actually be proved).
[center]Summary[/center]
As I noted above, the list of fallacious cases is well-nigh endless. But hopefully this short article will give someone with interest food for thought, thirst for discussion, greater appreciation for the potential that good argument offers the inquisitive mind, and a wholesome aversion to fallacies.