Thursday, August 26, 2004

Fallacies of Logic

This is a very small research paper for our Logic coursework that I did back in 2002. We had to find advertisements that committed fallacies and identify the types. I only have the typed material and not the ads so here is whatever I did minus the visuals. This is to one of my most favorite and influential teachers, Mr. Shuja.

Organization of the Report

The report has been organized in such a way that first, the fallacy has been defined and then the examples follow to make them easier to understand. In the first section, there is a brief introduction as to what a fallacy is and then the first type has been defined after which comes its subtypes. All sub fallacies are followed by examples in the order defined above.


A fallacy is an argument, which at first may seem to be correct but on examination and analysis, is found to be erroneous.

A fallacy is a bad argument because there are emotional appeals in the premises that are not logical but may be psychological. These logical errors are known as fallacies. If an argument contains a fallacy, then the conclusion will not necessarily be proven. Some fallacies are just accidental, but they can also be used to trap an unwary listener or reader into believing faulty conclusions.

There are two types of logical fallacies.

a. Fallacies of Relevance
b. Fallacies of Ambiguity

Fallacies of Relevance

Fallacies of relevance deal principally with the relationship between the premise and the conclusion of the argument. These fallacies have irrelevant premises i.e., the right conclusion is being drawn from wrong premises. The premises, in these fallacies, are psychological and not logically relevant.


This fallacy is committed when we move to quickly or carelessly from general to particular cases. This fallacy is also known as Hasty Generalization. In such a fallacy, the premise is general but the conclusion is particular.

Converse Accident

This fallacy is committed when we move to quickly or hastily from particular to general. It is also known as Misapplied Generalization. In this type of fallacy, the premise is particular whereas the conclusion is general.

Appeal to Force (Argument Ad Baculum)

The appeal to force is to cause the acceptance or rejection of some conclusion through force. Threats and intimidations used to force someone to accept an argument constitute an appeal to force.

False Cause

This fallacy is a matter of mistakenly believing that one event was caused by another event just because it happened after the other. The two events could have both been caused by another event, or they could be totally unrelated.

Argument Ad Hominem

This a logical as well as ethical fallacy as it is an argument directed towards men. The emphasis is on the person, group, event, or circumstances surrounding the issues. In such an argument, the personal character of an individual and/or his or her circumstances is logically irrelevant to the truth or falsehood of what that individual says or does.

There are two types of this fallacy.

a. Abusive or genetic fallacy, which is also known as Straw Man
b. Circumstantial or tu quoque fallacy

A. Argument Ad Hominem, Abusive

Disregarding a premise or an argument only because of where it came from commits the genetic fallacy where someone ridicules his or her opponent instead of addressing the premises. This fallacy also involves Guilt by Association, which means that if a person is accused due to his or her association with elements of bad repute. Another type of this fallacy is the Straw Man. When someone uses this fallacy, he or she applies a stereotype to his or her opponents to make them easy to refute.

B. Argument Ad Hominem, Circumstantial

This fallacy is used as a defense, where the person being criticized accuses his critic of doing the same thing himself. In this argument, someone’s particular traits are associated with the argument to win psychologically by saying something like everybody’s doing it so why can’t we. That is why it is also called the fallacy of Tu Quoque (you too).

Appeal to Ignorance (Argument Ad Ignorantiam)

When one assumes that, a premise is correct because it can't be disproved and vice versa, the fallacy of ignorance is committed. This is the "guilty until proven innocent" fallacy. Absence or presence of one kind of evidence is not proof as to the other.

Complex Question

A complex question is one that is phrased in such a way to unfairly limit the possibilities of one's answer to prove the conclusion through fallacious premises therein. It is a tricky question designed in such a way as to entrap the other person into negating or confirming without considering the hidden meaning.

Irrelevant Conclusion (Ignoratio Elenchi)

It is an argument that is irrelevant if it proves or disproves the wrong point. Ignoratio elenchi literally means false refutation and it is committed when you miss the point. In such a fallacy, the premise is plausible but the conclusion is not related to it.

Begging the Question (Petitio prinicpii)

This fallacy uses its conclusion as support of its premises. Therefore, it is also known as the fallacy of Circular Reasoning. In such a fallacy, the truth is presumed for proving what one wants to prove.

Ad Verecundiam (Appeal to Inappropriate Authority)

Using the opinion of an expert in a field other than the one being discussed may invalidate the argument therefore it is called appeal to in inappropriate authority. It is committed whenever the truth of some proposition is asserted based on the authority of one who has no special confidence in that particular field.

Argument Ad Populum (Appeal to Emotion)

This fallacy is committed when instead of giving relevant premises and logical grounds for the acceptance of conclusion, an appeal is made to emotions of the people, like enthusiasm, patriotism, excitement, anger, love or hatred.

Appeal to Fear

This is a subtype of the fallacy ad populum. In this fallacy however, the appeal is to the emotion of fear and the acceptance is made on the ground of instilling fear in the listener or reader.

Argument Ad Misericordium (Appeal to Pity)

This fallacy is a special case of argument ad populum. It is different from ad populum in that it appeals to one particular emotion: pity or sympathy.

Appeal to Flattery

This kind of fallacy is committed when being obsequious makes the appeal. The appeal is made by adulations to a person or a group.

Appeal to Humor

Another type of the argument ad populum, this fallacy is committed when the attention of the listener or reader is reverted to the humor incorporated in the premise that doesn’t support the conclusion.

Fallacies of Ambiguity

These fallacies deal principally with the misusage of words. An argument that contains improper or ambiguous use of words is invalid. Therefore, these fallacies are also known as Verbal Fallacies.

Arguments sometimes fail because their formulation contains ambiguous words or phrases, whose meanings shift and change with the course of the argument thus making it fallacious. A term is ambiguous in a context when that context does not rule out all its meanings but one i.e., the premises is in one sense but the conclusion is in a very different sense.

Figurative Use of Language

When an argument makes use of metaphors and similes, it is known as the figurative use of language.


Someone who uses a word in more than one sense, but gives the impression that only one meaning was meant, is using an equivocation. Anyone who presents an argument needs to use only one definition for each of his terms. When more than one definition is used for a certain word, it can cause confusion and be misleading.


A sentence that is structured in such a way as to make more than one interpretation possible is an amphiboly. Amphiboly literally means “two in a lump” and it is a fallacy committed through the misuse of grammar.

Prejudicial Use of Language

This fallacy is committed in the following two ways.

a. To use emotionally charged words in a neutral issue.
b. To use neutral language in an emotionally charged issue.


An argument is invalid when the shift in meaning within it arises from the changes in the emphasis given to its words or phrases. This shift in meaning may prove deceptive with stress on certain words in that sentence or argument.

December, 2002

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