Errors in Reasoning: 
Avoiding Logical Fallacies and Detecting Smokescreens

This set of definitions has been designed to help students learn critical reading and thinking skills.  Developed along with this  list of definitions are practices that help students identify thinking fallacies, smokescreens, and propaganda techniques.  The practices are  available at the Distance Reading Lab, a password-protected component of the HawCC Reading Lab web site.  User name and passwords are available through your reading instructor or Reading Lab Coordinator.  Once in the Distance Reading Lab, use the links marked More Reading Lab Activities and Practices, Advanced Critical Reading Skills and Practices, and Advanced Practices in Detecting Errors in Reasoning.

The definitions on this page provide an overview of  the numerous thinking fallacies that students may encounter daily.  The term fallacies comes from the Latin word for deceit.  It is easy to deceive ourselves into believing that we are making a strong argument when we have unintentionally lost our way. Some of the fallacies are purposely employed by writers and speakers for whom "winning" is everything. Most, however, are used by intelligent people who are unaware that they are resorting to fallacies.  Closely related to thinking fallacies are smokescreens and propaganda techniques that people deliberately use to deceive others.  You will find many examples of these in advertising and politics.

The definitions and practices have been adapted from the following sources:


Fallacies are used to avoid the issue, to confuse the issue, or merely to oversimplify the issue;  regardless, readers and listeners must be aware of these deceptions.  Sexism permeates society.  Stereotyping is common.  Rationalizations are accepted unthinkingly.  False authorities are commonly cited as authorities in the media.  The public is bombarded with loaded words and appeals to conformity.  Everyone  must maintain a constant guard lest they be lured into believing false promises, buying things sold on false premises, and being propagandized into false beliefs.   

Different authors define fallacies in different ways.  The following list is divided into two parts: those that are  most commonly used and those that are more difficult to detect.  The list provides an explanation of each fallacy and mentions some of the other names used to identify the same fallacy.    

I. Common Thinking Fallacies, Smokescreens, and Propaganda Techniques

Bandwagon Appeal

This fallacy is commonly used by politicians to influence people to vote for them.  "Ken Hughes - The People's Choice.  TV ads are also rife with images that illustrate the bandwagon appeal, for example shots of many people wearing the same type of jeans, or shoes, or using the same cleaning product.  The implications here is that if you don't jump on the bandwagon, the parade will pass you by.

 Card Stacking

This propaganda technique does not provide all of the information necessary for the reader to make an informed decision.  It uses arguments that support your position, but ignores or even denies the arguments against. Card stacking is often difficult to detect because you must decide  what is missing from the picture. 

Changing the Subject  

This fallacy includes the use of irrelevant information to support an argument and is sometimes referred to as the red herring fallacy.  Such facts  are distracting and unrelated, for example  "We need to spend more money on education.  Just because the Russians are increasing military spending doesn't mean we should.  The future of the nation depends on the children of today."  Mystery writers often use red herrings to lead the reader away from identifying the real culprit.

Circular Reasoning (Argument Ad Nauseam)* 

Using part of an argument as evidence to support it is called circular reasoning. "Mr. Green is a great teacher because he is so wonderful at teaching."  This fallacy "goes around in a circle;" the reason given is the same as the conclusion.


This is an example of black and white or dichotomous thinking.  This fallacy simplifies a complex problem so that only two options are presented.  They are stated in such a way as to make you believe that there are no other options. For example: "Some beach balls are yellow.  Some beach balls are red.  Therefore, if you have a beach ball it must be either yellow or red." Well, it might be; however, nowhere is it written that beach balls can't be blue or purple or multi-colored.  

False Comparison or Analogy

This is an argument that contains a contextual error or a neglected aspect.  It occurs when we assume that two things that are alike in one specific way are alike in other ways.  "Skis and roller skates are both strapped on your feet.  Skis help you travel over snow efficiently, so roller skates would help you travel efficiently over snow."

False Cause

The false cause fallacy assumes that because event B follows event A, Event B was caused by event A. Relationships are not cause and effect just because they occur at the same time.  "Statistics show that Hawaiians live longer than other Americans.  If you want to live longer you should move to Hawaii."  This "doubtful cause" fallacy is also called post hoc, ergo propter hoc ("after this, therefore because of this").  Another name is the improper data fallacy.  A generalization that attributes something to a false cause is based on faulty data.  "Janet and John both scored 98 on the history test; therefore John is as intelligent as Janet." (This does not take into account the fact that one of them studied for two days and one for half an hour.)    

Glittering Generalities (Argument by Slogan)

This is an important-sounding but unspecific claim.  It cannot be proved true or false because it really says little or nothing.  An example of a glittering generality is the promotion for a  popular beverage as "The Real Thing."  Here are some others : "Simply the best," "the Right Stuff," "Nutrition That Works." The point is that the phrase sounds good but says nothing definite.

Hasty Generalization

Someone who makes generalizations on the basis of insufficient evidence is making a hasty generalization.  "The first six people who voted all said they had voted Democratic.  It looks like a big victory for Democrats this election."  This fallacy can also be called  stereotyping, a generalization that results from an oversimplification or a bias.  For example,   "Blonds are dumb" or "Chinese are clever." Still another name for this fallacy might be the inadequate data fallacy.   The user of this fallacy has some data pertinent to the problem but not enough to form the basis of a sound conclusion.  The media's rush to interpret early voting results out of Florida for the 2000 Presidential election was clearly hasty.  

Loaded Words

This is also called the glad and bad words fallacy.  It involves the use of emotive words to influence the reader.  This technique is frequently used in advertisements to persuade us to buy things.  Bad words are used to make us buy products to rid ourselves of things that we have been persuaded are undesirable.  Glad words are used to make us buy products to obtain what we have been persuaded is desirable.  Some ads use both techniques.  "Why suffer the embarrassment of morning mouth?  Use ZYX toothpaste every evening and wake up to a fresh, exciting mouth."

Name Calling and Personal Attack (Ad hominem)

Name calling uses derogatory implications or innuendos to turn people against a rival.  For example, in the political world, one group may call another group's beliefs "un-American" when what all they really mean is that they disapprove of those ideas.  In the business world, Burger King employs this technique to imply that its burgers are superior to McDonalds.

The personal attack fallacy narrows in on the character of the opponent instead of addressing the issue at hand, and often occurs in political debate. "Our Mayor's opinions about local crime are worthless.  He can't even manage to hold his own household together, having been married and divorced three times already." 

Plain Folks

The Plain Folks technique  is commonly used in advertisements and is similar to the Testimonial technique outlined below. Ordinary  people are pictured in print ads or appear on television endorsing products.  The advertiser uses people who reminds of  Grandma, the "conventional" family of mother, father, son and daughter, and even adorable babies and pets to help sell the product.  This  is also known as the false authority fallacy.

Slippery Slope

The assumption that one event can  cause of an undesirable chain reaction of events.  The slippery slope fallacy is a case of if-then.  For example, "If you don't get to bed early, then you'll be too tired to do well on the GRE tomorrow.  If that happens, then you won't get accepted into a decent graduate school, and you'll end up a washed-out alcoholic living in a trash-bin."  There is also an old saying about a camel's nose that is another example of slippery slope: "If you allow a camel to poke his nose into the tent, soon the whole camel will follow."*

Straw Man

Because it is easier to demolish a man of straw than to beat a live opponent fairly, arguers are sometimes tempted to pretend that they are responding to the views of their opponents when they are only setting up a type of artificial opposition which they can easily prove to be wrong.  A common form of the straw man fallacy is to attribute to others views that they do not actually hold.  This fallacy almost always avoids the real issue. An example would be arguing against defense spending by claiming that peace is more desirable than war.  Since almost everyone believes the war is undesirable, this argument avoids the more difficult question of how peace is secured.  This fallacy is closely related to the personal attack and name calling fallacies explained above but appears to be a more sophisticated effort to deceive the public.  The user of the Straw Man strategy must cleverly reinvent his opponent in order to change the public's initial perception of that opponent.


This is commonly used in advertisements. It is similar to the Plain Folks technique explained above. However, instead of ordinary people, famous people are pictured in print ads or appear on television endorsing products.  The advertiser hopes that those who admire this person will buy the products thinking that they will be more like their idol if they use products he or she uses.  Testimonial  is another form the false authority fallacy.


This fallacy appeals to people's respect or reverence of symbols, such as a politician standing in front of an American flag.  There is also a good deal of transfer value in children, pets, or good-looking models.


II. Fallacies That Are More Difficult to Detect

Conventional Wisdom

This fallacy occurs when arguments are based on clichés or on "facts" that "everybody knows." "The pen is mightier than the sword, so if you are ever in a fight grab a pen to defend yourself."


This involves stating facts and opinions in the same argument in such a way that the listener confuses the two.  "Betsy Ross made the first American flag.  She must have been the finest seamstress in the thirteen colonies."  


When we rationalize, we give ourselves good reasons for doing things we want to do and good reasons for avoiding things we wish to avoid, but these good reasons are not really true.  "Mark sees a shirt on sale in the store.  He does not need the shirt, but buys it anyway because 'it was so cheap I couldn't afford not to buy it.' "


This occurs when there is an inconsistency in reasoning.  "Inebriated drivers are more careful than sober drivers because they know that drunk drivers are more likely to be involved in accidents."  


The most common fallacy, and the one that is most difficult to be aware of, is the sexism fallacy.  English speaking people have historically used masculine pronouns when referring to groups that can be either male or female.  We have been socialized to accept the fallacious belief that the male is superior to the female.  The statement "Doctors should spend-more time with their wives and children" assumes that all doctors are male. 

Shifty Word 

As an educated individual you must learn to recognize the semantic implications of polysemantic words and homonyms.  Many words in the English language have multiple meanings and you must be able to make the transition from one meaning to another.  You  must also be able to distinguish between words that sound alike but are spelled differently and have different meanings.  Many riddles rely on the shifty word fallacy.  For example, "What is black and white, yet read (red) all over?  The newspaper."  Those who use the shifty word fallacy are accused of ambiguity and equivocation.   

 *For a nearly exhaustive list of argument fallacies, check out this web site created by Don Lindsay : A List Of Fallacious Arguments.  These starred items were taken from this list.

This list of definitions has been adapted and edited by Amritana Engle, Spring 2001.