Detecting Fallacies
One way of avoiding fraud is to be able to detect fallacies when you hear or read them. The following are some of the different types of fallacies.
Ambiguity
These are cases where a word or phrase is used uncleanly. There are two ways in which this may occur:
- The word or phrase may be ambiguous, in which case it has more than one distinct meaning.
- The word or phrase may be vague, in which case it has no distinct meaning.
Accent
Emphasis is used to suggest a meaning different from the actual content of the proposition. For example:
"It would be illegal to give away Free Beer!"
"The first mate, seeking revenge on the captain, wrote in his journal, "The Captain was sober today!" (He suggests, by his emphasis, that the Captain is usually drunk.)
Appeals to motives in place of support
Appeals to motives in place of support are fallacies that have in common the practice of appealing to emotions or other psychological factors instead of providing reasons for belief.
Argumentum ad Baculum (Appeal to Force)
An Appeal to Force happens when someone resorts to force, or the threat of force, in an attempt to push others into accepting a conclusion. This fallacy is often used by politicians. It may be summarized as "might makes right." The threat need not come directly from the person arguing. For example:
"I know your phone number. Some people who have disagreed with me had received threatening phone calls."
"If you don't agree with the new tournament rules, you students may never win again."
Argumentum ad Misericordiam
This is the Appeal to Pity, also known as Special Pleading. This fallacy is committed when someone appeals to pity for the sake of getting a conclusion accepted. The reader is told to agree to the proposition because of the pitiful state of the author. For example:
"I did not murder my mother and father with an axe! Please do not find me guilty; I am suffering enough from being an orphan."
"How can you say that's not a point? It was so close, and besides, I'm down way down in points."
"I hope you'll like my pattern. I spent the last three months working on it."
Appeal to Consequences (argumentum ad consequentiam)
The author points to the disagreeable consequences of holding a particular belief in order to show that this belief is false. For example:
"You can't believe Taekwondo is any good for self-defense; those high kicks will get you killed if you use them on the street."
"You must believe in God, for otherwise life would have no meaning."
Argumentum ad Populum (Appealing to the Gallery or Appealing to the People)
This fallacy is known as You commit this fallacy if you attempt to win acceptance of an assertion by appealing to a large group of people. A proposition is held to be true because it is widely held to be true or is held to be true by some upper class sector of the population. This form of fallacy is often characterized by emotive language. It is sometimes also called the "Appeal to Emotion" because emotional appeals often sway the population as a whole. For example:
"Millions of people believe in acupuncture. Are you telling those people that they are all mistaken fools?"
"Taekwondo is the most practiced martial art in the United States so you might as well study it rather than lesser known martial arts."
Category of errors
These fallacies occur because the author mistakenly assumes that the whole is nothing more than the sum of its parts. However, things joined together may have different properties as a whole than any of them do separately.
Composition
Because the parts of a whole have a certain property, it is argued that the whole has that property. That whole may be either an object composed of different parts, or it may be a collection or set of individual members. For example:
"The brick wall is six feet tall. Thus, the bricks in the wall are six feet tall."
"Judo is a gentle art. Thus, each Judo player is gentle.".
Division
Because the whole has a certain property, it is argued that the parts have that property. The whole in question may be either a whole object or a collection or set of individual members. For example:
"Because the brain is capable of consciousness, each neural cell in the brain must be capable of consciousness."
Casual
It is common for arguments to conclude that one thing causes another. But the relation between cause and effect is a complex one. It is easy to make a mistake. In general, we say that a cause C is the cause of an effect E if, and only if:
- Generally, if C occurs, then E will occur, and
- Generally, if C does not occur, then E will not occur.
- We say "generally" because there are always exceptions. For example, we say that striking the match causes the match to light, because:
- Generally, when the match is struck, it lights, and
- Generally, when the match is not struck, it does not light.
Many writers also require that a causal statement be supported with a natural law. For example, the statement that "striking the match causes it to light" is supported by the principle that "friction produces heat, and heat produces fire".
Post Hoc Ergo Propter Hoc
The name in Latin means "after this therefore because of this". This fallacy occurs when something is assumed to be the cause of an event merely because it happened before that event. This is another type of false cause fallacy. For example:
"Taekwondo is based on Karate since Karate was developed before Taekwondo."
"The vitamin must work because two days after I started using it, my cold went away."
Joint Effect
One thing is held to cause another when in fact both are the effect of a single underlying cause. This fallacy is often understood as a special case of Post Hoc Ergo Prompter Hoc. For example:
"You have a fever and that is causing you to break out in spots." (In fact, both symptoms are caused by the measles.)
Genuine but Insignificant Cause
The object or event identified as the cause of an effect is a genuine cause, but insignificant when compared to the other causes of that event. Note that this fallacy does not apply when all other contributing causes are equally insignificant. Thus, it is not a fallacy to say that you helped defeat the incumbent because you voted for her opponent because your vote had as much weight as any other vote, and hence is equally a part of the cause. For example:
"Smoking is causing air pollution."
"By leaving your oven on overnight, you are contributing to global warming."
Complex Cause
The effect is caused by a number of objects or events, of which the cause identified is only a part. A variation of this is the feedback loop where the effect is itself a part of the cause. For example:
"The Challenger explosion was caused by the cold weather. (True, however, it would not have occurred had the O-rings been properly constructed.)
"People are in fear because of increased crime. (True, but this has led people to break the law as a consequence of their fear, which increases crime even more.)
Changing the subject
These fallacies change the subject by discussing the person making the argument instead of discussing reasons to believe or disbelieve the conclusion. While sometimes it may be useful to cite authorities, it is almost never appropriate to discuss the person instead of the argument.
Argumentum ad Hominem
Argumentum ad hominem literally means "argument directed at the man." The person presenting an argument is attacked instead of the argument itself. For example, the person's character, nationality or religion may be attacked, or, it may be pointed out that a person stands to gain from a favorable outcome, or, a person may be attacked by association or by the company he or she keeps. There are three major forms of Attacking the Person:
(1) ad hominem (abusive): is the abusive form where a person refuses to accept a statement, and justifies the refusal by criticizing the person who made the statement.
"You claim that Taekwondo is effective on the street but yet you have been seriously injured during street attacks."
This is a fallacy because the truth of an assertion does not depend on the virtues of the person asserting it. A less blatant form of this fallacy is to reject a proposition based on the fact that it was also asserted by some other easily criticized person. For example:
"So you think the best way to teach a class is to run the class in a military manner. I am sure the Hitler and Stalin would have agreed with you."
(2) ad hominem (circumstantial): instead of attacking an assertion, the author points to the relationship between the person making the assertion and the person's circumstances .For example:
"You must not stress physical fitness in your style of Karate, since you are obviously obese."
(3) ad hominem (tu quoque): this form of attack on the person notes that a person does not practice what he or she preaches. You may also allege that someone is rationalizing a conclusion for selfish reasons, is also known as "poisoning the well." It is not always invalid to refer to the circumstances of an individual who is making a claim. If someone is a known liar, that fact will reduce his or her credibility. However, this may not prove that he or she is lying in a particular statement. Also, being a liar does not alter the soundness of any logical arguments that the person may make. For example:
"Of course you believe that there is no discrimination in Taekwondo schools. You are white."
"You say I shouldn't drink, but you haven't been sober for more than a year."
Argumentum ad Verecundiam (Appeal to Authority)
While sometimes it may be appropriate to cite an authority to support a point, often it is not. In particular, an appeal to authority is inappropriate if:
The person is not qualified to have an expert opinion on the subject, such as a celebrity. For example:
"Shirley McLain is a great actress, and she believes in psychics."
Experts in the field disagree on this issue. For Example:
"Economist John Kenneth Galbraith argues that a tight money policy is the best cure for a recession." (Although Galbraith is an expert, not all economists agree on this point.)
The authority was making a joke, drunk, or otherwise not being serious. For example:
"We are headed for nuclear war. Last week Ronald Reagan remarked that we begin bombing Russia in five minutes." (Of course, he said it as a joke during a microphone test.)
A variation of the fallacious appeal to authority is hearsay. An argument from hearsay is an argument which depends on second or third hand sources. For example:
"My friend heard on the news the other day that Canada will declare war on Serbia. (This is a case of hearsay; in fact, the reporter said that Canada would not declare war.)
This appeal to authority argument is not always invalid. It may be relevant to refer to a widely-regarded authority in a particular field, if you are discussing that field. For example: we can distinguish quite clearly between:
"Phillip Porter thinks that chokes are an effective self-defense tactic."
and
"Sugar Ray Leonard thinks that board breaking serves no useful purpose."
Porter is a 10th degree black belt in Judo, so we can reasonably expect his opinions on choking to be informed. Leonard is a boxer, so it is questionable whether he is qualified enough to speak on the subject of board breaking.
Anonymous Authorities
The authority in question is not named. This is a type of appeal to authority because when an authority is not named it is impossible to confirm that the authority is an expert. However, the fallacy is so common it deserves special mention. A variation on this fallacy is the appeal to rumor. Because the source of a rumor is typically not known, it is not possible to determine whether to believe the rumor. Very often false and harmful rumors are deliberately started to discredit an opponent. For example:
"Self-defense experts agree that traditional martial arts are useless on the streets."
"Rumor has it that Bruce Less died of a drug overdose"
Style Over Substance
The manner in which an argument (or arguer) is presented is taken to affect the likelihood that the conclusion is true. While it is true that the manner in which an argument is presented will affect whether people believe that its conclusion is true, nonetheless, the truth of the conclusion does not depend on the manner in which the argument is presented. For example:
"Nixon lost the presidential debate because of the sweat on his forehead."
"The instructor is overweight and out of shape. I wouldn't believe what he says about the martial arts."
Distraction
Fallacies of distraction are characterized by the illegitimate use of a logical operator to distract the reader from the apparent falsity of a certain proposition.
False Dilemma
A limited number of options (usually two) is given, while in reality there are more options. A false dilemma is an illegitimate use of the "or" operator. For example:
"Either you're for me or against me."
"America: love it or leave it."
"In fighting situation, Taekwondo practitioners will either kick or punch."
Argumentum ad Ignorantiam
Argumentum ad ignorantiam means "argument from ignorance." This fallacy occurs when it is argued that something must be true, simply because it has not been proven false. Or, vice versa. Lack of proof is not proof. This is not the same as assuming something is false until it has been proved true, as in the justice system where you are assumed innocent until proven guilty. This is a special case of a False Dilemma, since it assumes that all propositions must ether be known to be true or known to be false. For example:
"Of course pet psychics are real. Nobody can prove otherwise."
"Of course pet psychics are fakes. Nobody has shown any proof that they are real."
In scientific investigation, if it is known that an event would produce certain evidence of its having occurred, the absence of such evidence can validly be used to infer that the event did not occur. However, it does not prove it with certainty. For example:
"A flood as described in the Bible would require an enormous volume of water to be present on the earth. The earth does not have nearly that much water, even if the water frozen into ice at the poles is used. Therefore no such flood occurred."
However, it is possible that some unknown process occurred to remove the water after the flood. Good science would then demand a plausible testable theory to explain how it vanished.
Slippery Slope
To show that a proposition P is unacceptable, a sequence of increasingly unacceptable events is shown to follow from P. A slippery slope is an illegitimate use of the "if-then" operator. For example:
"If I make an exception for you then I have to make an exception for everyone."
"If we pass laws against fully-automatic weapons, then it won't be long before we pass laws on all weapons, and then we will begin to restrict other rights, and finally we will end up living in a communist state. Thus, we should not ban fully-automatic weapons."
Complex Question
Two otherwise unrelated points are conjoined and treated as a single proposition. The reader is expected to accept or reject both together, when in reality one is acceptable while the other is not. A complex question is an illegitimate use of the "and" operator. For example:
"Do you support Taekwondo and believe it is the best martial art?"
"Have you stopped using steroids?" (This asks two questions: did you use steroids and did you stop?)
Inductive
Inductive reasoning consists of inferring from the properties of a sample to the properties of a population as a whole. For example, suppose we have a barrel containing 1,000 marbles. Some of the marbles are black and some of the beans are white. Suppose now we take a sample of 100 marbles from the barrel and that 50 of them are white and 50 of them are black. We could infer inductively that half the marbles in the barrel are black and half are white. All inductive reasoning depends on the similarity of the sample and the population. The more similar the sample is to the population as a whole, the more reliable will be the inductive inference. However, if the sample is relevantly dissimilar to the population, then the inductive inference will be unreliable. No inductive inference is perfect. Even though the premises are true, the conclusion might be false. Nevertheless, a good inductive inference gives us a reason to believe that the conclusion is probably true.
Hasty Generalization
The size of the sample is too small to support the conclusion. For example:
"A Taekwondo student was mugged last night. That just proves that Taekwondo is useless on the street."
"I asked a friend if the school has a good instructor. He said "No" so the instructor must not be any good."
False Analogy
In an analogy, two objects (or events), A and B, are shown to be similar. Then it is argued that, since A has property P, so also B must have property P. An analogy fails when the two objects, A and B, are different in a way which affects whether they both have property P. For example:
"Students are like nails. Just as nails must be hit in the head in order to make them work, so must students."
Fallacy of Exclusion
Important evidence which would undermine an inductive argument is excluded from consideration. The requirement that all relevant information be included is called the "principle of total evidence." For example:
"A Taekwondo student got beat in a street fight last night." (The information left out is that he was attacked by four opponents."
Missing the point
These fallacies have in common a general failure to prove that the conclusion is true.
Petitio Princippi (Begging the Question)
This fallacy occurs when the premises are at least as questionable as the conclusion reached. The truth of the conclusion is assumed by the premises. Often, the conclusion is simply restated in the premises in a slightly different form. In more difficult cases, the premise is a consequence of the conclusion. Typically the premises of the argument implicitly assume the result which the argument purports to prove, in a disguised form.\
For example:
"The Bible is the word of God. The word of God cannot be doubted, and the Bible states that the Bible is true. Therefore the Bible must be true.
"Since I'm not lying, it means that I'm telling the truth."
Begging the question is similar to Circulus in Demonstrando, where the conclusion is exactly the same as the premise.
Ignoratio Elenchi (Irrelevant Conclusion)
This fallacy consists of claiming that an argument supports a particular conclusion when it actually has nothing logically to do with that conclusion. It is also an argument which purports to prove one thing but instead proves a different conclusion. For example:
"A student may begin by saying that he will argue that the teachings of Bodhidharma are undoubtedly true. If he then argues at length that the teaching are of great help to many people, no matter how well he argues, he will not have shown that the teachings are true. Sadly, these kinds of irrelevant arguments are often successful, because they cause people to view the supposed conclusion in a more favorable light."
"I say we should support affirmative action. White males have run the country for 500 years. They run most of government and industry today. You can't deny that this sort of discrimination is intolerable." (The author has proven that there is discrimination, but not that affirmative action will end that discrimination.
Straw Man
The author attacks an argument which is different from, and usually weaker than, the opposition's best argument. For example:
"We should have conscription. People don't want to enter the military because they find it an inconvenience. But they should realize that there are more important things than convenience."
Non- sequitur
The term non-sequitur literally means "it does not follow". These fallacies occur as a consequence of invalid arguments.
Affirming the Consequent
Any argument of the following form is invalid:
If A then B
B
Therefore, A
For example:
"If I am in Atlanta, then I am in Georgia. I am in Georgia, thus, I am in Atlanta."
"If my self-defense system works, then the self-confidence you present will deter others from confronting you. You have not been confronted since you began training in my system. Thus, my system works."
Denying the Antecedent
Any argument of the following form is invalid:
If A then B
Not A
Therefore, Not B
For example:
"If you get hit by a car when you are six then you will die young. But you were not hit by a car when you were six. Thus you will not die young."
"If I am in Atlanta then I am in Georgia. I am not in Atlanta, thus, I am not in Georgia."
Inconsistency
The author asserts more than one proposition such that the propositions cannot all be true. In such a case, the propositions may be contradictories or they may be contraries. For example:
"Greensboro is about 30 miles from Winston-Salem. Burlington is 10 miles from Winston-Salem. Therefore, Burlington is closer to Winston-Salem than Greensboro."
"John is taller than Jake, and Jake is taller than Fred, while Fred is taller than John."
Statistical syllogism
A statistical generalization is a statement which is usually true, but not always true. Very often these are expressed using the word "most", as in "Most students can't kick effectively." Sometimes the word "generally" is used, as in "Generally, students can't kick effectively." Or, sometimes, no specific word is used, as in: "Students can't kick effectively." Fallacies involving statistical generalizations occur because the generalization is not always true. Thus, when an author treats a statistical generalization as though it were always true, the author commits a fallacy.
Accident
A general rule is applied when circumstances suggest that an exception to the rule should apply. For example:
"You should be you should be trained in Taekwondo before using it to protect a person. Therefore, even though the child was being abducted, you should not have used Taekwondo technqiues to free the child."
Converse Accident
An exception to a generalization is applied to cases where the generalization should apply. For example:
"Because you awarded a black belt to the student with one leg without him having to do the required kicks, you should should waive the kicking requirements for all the students."
Bifurcation (Black and White Fallacy or False Dichotomy)
Bifurcation occurs if someone presents a situation as having only two alternatives, when in fact, other alternatives exist or may exist. For example:
"There are only two versions of Taekwondo history, one as described by the WTF and the other as described by the ITF."
Circulus in Demonstrando
This fallacy occurs if you assume as a premise the conclusion that you wish to reach. Often, the proposition is rephrased so that the fallacy appears to be a valid argument. For example:
"Because of the threat of AIDS, homosexuals should not be allowed in a Taekwondo class. Any student who is revealed to be a homosexual should be expelled. Therefore, homosexual students will do anything they can to hide their secret, and will be open to threats of exposure. Therefore, homosexuals should not be allowed in a Taekwondo class."
Note that the argument is entirely circular; the premise is the same as the conclusion. Circular arguments are surprisingly common. If you have already reached a particular conclusion once, it is easy to accidentally make it an assertion when explaining your reasoning to someone else.
Complex Question (Fallacy of Interrogation or Fallacy of Presumption)
This is the interrogative form of Begging the Question. One example is the classic loaded question:
"Have you stopped beating your wife?"
The question presupposes a definite answer to another question that has not been asked. This trick is often used by lawyers in cross-examination, when they ask questions like:
"Where did you hide the money you stole?"
Similarly, politicians often ask loaded questions such as:
"How long will this United Nations interference in our affairs be allowed to continue?"
Another form of this fallacy is to ask for an explanation of something which is untrue or not yet established.
Fallacy of Composition
Opposite of Fallacy of Division. This fallacy is to conclude that a property shared by a number of individual items, is also shared by a collection of those items, or that a property of the parts of an object, must also be a property of the whole thing. For example:
"Many of the students in the class think the Taekwondo instructor is a good teacher, therefore, the class must think the instructor is a good teacher."
Converse Accident (Hasty Generalization)
This is the reverse of the Fallacy of Accident. It occurs when you form a general rule by examining only a few specific cases that are not representative of all possible cases. For example:
"The Taekwondo opponent I fought at the tournament was a bad fighter. Therefore, all Taekwondo practitioners are bad fighters."
Converting a Conditional
This fallacy is an argument of the form "If A then B, therefore, if B then A."
"As the rank promotion requirements are lowered, more students will be earning black belts. So, if we see the number of black belts increasing over the next few years, we will know that the promotion requirements are still being lowered."
This fallacy is similar to the Affirmation of the Consequent, but phrased as a conditional statement.
Cum Hoc Ergo Propter Hoc
This fallacy is similar to Post Hoc Ergo Prompter Hoc. The fallacy is to assert that because two events occur together, they must be causally related. It is a fallacy because it ignores other factors that may be the cause(s) of the events.
"Rank testing failures have increased since Elmo starting teaching. Elmo must not be a good teacher."
This fallacy is a special case of the more general Non Causa Pro Causa.
Denial of the Antecedent
This fallacy is an argument of the form "A implies B, A is false, therefore, B is false." The truth table for implication displayed in the arguments topic shows why this is a fallacy.This fallacy is different from Non Causa Pro Causa that has the form "A implies B, A is false, therefore, B is false", where A does not in fact imply B at all. Here, the problem is not that the implication is invalid, instead, it is that the falseness of A does not allow us to deduce anything about B. This is the converse of the fallacy of Affirmation of the Consequent. For example:
"If a UFO appeared before me, it would prove that UFO's are real. But none ever appeared before me, so cases of alien abductions must be false."
Dicto Dimpliciter (Fallacy of Accident or Sweeping Generalization)
A sweeping generalization occurs when a general rule is applied to a particular situation, but the features of that particular situation mean the rule is inapplicable. It is the error made when you go from the general to the specific. This fallacy is often committed by people who try to decide moral and legal questions by mechanically applying general rules. For example:
"Most ITF students dislike WTF students. You are a ITF student, so you must dislike WTF students."
Fallacy of Division
This is the opposite of the Fallacy of Composition. It consists of assuming that a property of something must apply to its parts, or that a property of a collection of items is shared by each item.
"You train at dojang known for its good fighters. Therefore, you must be a good fighter."
Equivocation (Fallacy of Four Terms)
Equivocation occurs when a key word is used with two or more different meanings in the same argument. One way to avoid this fallacy is to choose your terminology carefully before beginning the argument, and avoid words that have many meanings. For example:
"I have heard that your school has some "bad" black belts. I do not want my child to attend the school because I do not want him exposed to bad behavior by senior ranks."
Extended Analogy
This fallacy often occurs when some suggested general rule is being argued over. The fallacy is to assume that mentioning two different situations, in an argument about a general rule, constitutes a claim that those two situations are analogous to each other. For example, the following is an argument about sharing music over the Internet:
"I believe it is always wrong to oppose the law by breaking it."
"Such a position is odious: it implies that you would not have supported Martin Luther King."
"Are you saying that music sharing is as important as the struggle for racial equality?"
Natural Law Fallacy (Appeal to Nature)
This is a common fallacy in political arguments. One version consists of drawing an analogy between a particular conclusion, and some aspect of the natural world, and then stating that the conclusion is inevitable, because the natural world is similar. For example:
"The natural world is characterized by competition; animals struggle against each other for ownership of limited natural resources. Fighting over ownership is simply an inevitable part of human nature. It is how the natural world works."
Another form of appeal to nature is to argue that because human beings are products of the natural world, we must mimic behavior seen in the natural world, and that to do otherwise is "unnatural." For example
"To defend ourselves using a set pattern of techniques is unnatural. To be effective a self-defense, we must mimic the way animals fight in nature."
"No True Scotsman" Fallacy
Suppose I assert that no Scotsman puts sugar on his porridge. You counter this by pointing out that your friend Angus likes sugar with his porridge. I then say "Ah, yes, but no "true" Scotsman puts sugar on his porridge.
This is an example of an ad hoc change being used to shore up an assertion, combined with an attempt to shift the meaning of the words used original assertion. It is sort of a combination of fallacies.
Non Causa Pro Causa (False Cause Fallacy)
This fallacy occurs when something is identified as the cause of an event, but it has not actually been shown to be the cause. For example:
"I took an aspirin and the master rubbed my temples, and my headache disappeared. So the master cured me of the headache."
Non Sequitur
A non sequitur is an argument where the conclusion is drawn from premises that are not logically connected with it. Non sequiturs are an important ingredient in a lot of humor. For example:
"Since Egyptians did so much excavation to construct the pyramids, they were well versed in paleontology."
Red Herring
This fallacy is committed when someone introduces irrelevant material to the issue being discussed, so that everyone's attention is diverted away from the points made toward a different conclusion. For example:
"You may claim that the death penalty is an ineffective deterrent against crime -- but what about the victims of crime? How do you think surviving family members feel when they see the man who murdered their son kept in prison at their expense? Is it right that they should pay for their son's murderer to be fed and housed?"
Shifting the Burden of Proof
The burden of proof is always on the person asserting something. Shifting the burden of proof, a special case of Argumentum ad Ignorantiam, is the fallacy of putting the burden of proof on the person who denies or questions the assertion. The source of the fallacy is the assumption that something is true unless proven otherwise.
"OK, so if you do not think Ki is an energy that actually flows through the body, can you prove it?"
Slippery Slope Argument
This argument states that should one event occur, so will other harmful events, even though here is no proof made that the harmful events are caused by the first event. For example:
"If we legalize marijuana, then more people would start to use crack and heroin, and we would have to legalize those too. Before long we would have a nation full of drug-addicts on welfare. Therefore, we cannot legalize marijuana."
Straw Man Fallacy
The straw man fallacy is when you misrepresent someone else's position so that it can be attacked more easily. Then you knock down that misrepresented position and conclude that the original position has been demolished. It is a fallacy because it fails to deal with the actual arguments that have been made.
"To believe that your martial art is the best, you must examine all the martial art styles in the world. Since you obviously have not done this, your position is indefensible."
Shifting the Burden of Proof
The burden of proof is always on the person asserting something. Shifting the burden of proof, a special case of Argumentum ad Ignorantiam, is the fallacy of putting the burden of proof on the person who denies or questions the assertion. The source of the fallacy is the assumption that something is true unless proven otherwise.
"OK, so if you do not think Ki is an energy that actually flows through the body, can you prove it?"
Tu Quoque
This is the famous "you too" fallacy. It occurs if you argue that an action is acceptable because your opponent has performed it. For example:
"You are hitting too hard."
"So what? You have also been hitting too hard."
This is a personal attack, and is therefore a special case of Argumentum ad Hominem.
Fallacy of the Undistributed Middle ("A is based on B" Fallacies or "...is a type of..." Fallacies)
These fallacies occur if you attempt to argue that things are in some way similar, but you do not actually specify in what way they are similar. For example:
"Taekwondo throws are based on Judo throws? Therefore, is not Taekwondo just a form of Judo?"
Other types
Accent
This fallacy uses a shifted meaning, where the meaning is changed by altering which parts of a statement are emphasized. For example:
"I can say any thing bad about Taekwondo."
Does this mean your cannot say anything bad about Taekwondo because it is all good, or does it mean there are bad things to say but you are not permitted to say them. Be particularly wary of this fallacy while browsing the Internet, since it is easy to misread the emphasis of what has been written.
Ad Hoc
As mentioned in the arguments topic, there is a difference between an argument and an explanation. If in trying to establish A as true, B is offered as evidence, the statement "A because B" is an argument. If trying to establish the truth of B, then "A because B" is not an argument, it is an explanation.
The Ad Hoc fallacy is used to give an after-the-fact explanation that does not apply to other situations. Often it will appear to be an argument. For example, if we assume that the master treats all his students equally, then the following is an ad hoc explanation:
"The master healed my headache."
"So, will he heal others who have headache?"
"Maybe, the ways of the master are mysterious."
Affirmation of the Consequent
This fallacy is an argument of the form "A implies B, B is true, therefore A is true." To understand why it is a fallacy, examine the truth table for implication displayed in the arguments topic. This is the converse of Denial of the Antecedent fallacy. For example:
"If the universe had been created by a supernatural being, we would see order and organization everywhere. Since we do see order and not randomness, it is clear that the universe had a creator."
Argumentum ad Logicam
This is the "fallacy fallacy" of arguing that a proposition is false because it has been presented as the conclusion of a fallacious argument. Remember, fallacious arguments may arrive at true conclusions. For example:
"Take the fraction 16/64. Now, canceling a six on top and a six on the bottom, the result shows that 16/64 = 1/4."
"Wait a second! You can't just cancel the six!"
"Oh, so are you telling me that 16/64 is not equal to 1/4?"
Argumentum ad Nauseam
This fallacy is the incorrect belief that an assertion is more likely to be true, or is more likely to be accepted as true, the more often it is heard. This fallacy uses constant repetition in asserting something; saying the same thing over and over until you are sick of hearing it. For example:
"Democrats care more for the poor than do republicans."
Argumentum ad Novitatem
This is the opposite of the Argumentum ad Antiquitatem. It is the fallacy of asserting that something is better, or more correct, simply because it is new, or newer than something else. For example:
"Olympic styte Taekwondo is better than traditional Taekwondo because it uses modern techniques."
Argumentum ad Numerum
This fallacy is closely related to Argumentum ad Populum. It consists of asserting that the more people who support or believe a proposition, the more likely it is that the proposition is correct. For example:
"Taekwondo is the most practiced martial art in the United States. Since it is so widely used, it must be the best martial art."
Audiatur et Altera Pars
People often argue from assumptions that they do not bother to state. The principle of Audiatur et Altera Pars is that all of the premises of an argument should be stated explicitly. It is not strictly a fallacy to fail to state all your assumptions; however, it is often viewed with suspicion.