Types of Logical Fallacy







Arguments and the logical fallacies they use can be grouped into 5 categories:
  1. Deductive Logic Arguments (Abstract World Arguments): this group of arguments use deductive logic. They don't use physical world testing evidence to justify their conclusions and/or they are arguments that cannot be tested in the physical world. Typically they start with premises (the premises define the particular abstract world) and from these premises deductions are made. This group includes the deductive logic fallacies.
  2. Irrelevant Arguments: This group of arguments use the introduction of irrelevant or incorrect factors to stop the logical flow of the core argument.
  3. Denial ArgumentsIt is always possible to deny any logic or physical world evidence. This group of arguments are based on the unreasonable denial of physical world evidence or logical consistency.
  4. Inductive Logic Arguments (Physical World Inductive Logic): This group of arguments use physical world evidence and inductive logic.  However, there is no physical world testing of predicted outcomes looking for negative and positive evidence. The group includes inductive logical fallacies.
  5. Physical World Tested Arguments: This group of arguments use deductive logic and test in the physical world what the idea predicts looking for negative and positive evidence. They don't claim to prove an idea but can disprove an idea and rank the idea's usefulness. 

Taxonomy

Using the 5 categories and the following taxonomy can be created.
 
 

1) Deductive Logic Arguments and Fallacies


Abstract World argument

Affirming the consequence

When the antecedent in an indicative conditional is claimed to be true because the consequent is true.

If Bill Gates owns Fort Knox, then he is rich.
Bill Gates is rich.
Therefore, Bill Gates owns Fort Knox.

Fallacy of necessity
A degree of unwarrented necessity is placed in the conclusion based on the necessity of one or more of its premises. Example:

    a) Bachelors are necessarily unmarried.
    b) John is a bachelor.
    Therefore, c) John cannot marry. 

False dichotomyArbitrarily reducing a set of many possibilities to only two. For example, it might be argued that a bar must be shut down for it to not cause disturbing levels of noise after midnight. This ignores the fact that the bar could simply lower its noise levels, and/or install more soundproof structural elements to keep the noise from excessively transmitting onto others' properties. (assumes these are the only two possibilities).
TautologiesJustifying an argument by using circular reasoning. For example saying that therapeutic touch works because it manipulates the life force is a tautology because the definition of therapeutic touch is the alleged manipulation (without touching) of the life force.
AnalogyArgument by analogy - For example, if A. Plato was mortal, and B. Plato was just like Socrates, then asserting that, therefore C. Socrates was mortal.
Failed argument
Argument A for the conclusion C is unsound. 
Therefore, C is false. An example of this would be arguing that a conclusion is false because an argument  given for it is bad. 
 Reductio ad absurdumIf an argument is valid then expand the argument to the most extreme. Challenge the extreme and use that invalidate the original argument.
 Unstated Major PremiseOne makes an argument which assumes a premise which is not explicitly stated. Arguing that we should label food products with their cholesterol content because Americans have high cholesterol assumes that: 1) cholesterol in food causes high serum cholesterol; 2) labeling will reduce consumption of cholesterol; and 3) that having a high serum cholesterol is unhealthy.




2) Irrelevant  Arguments


Irrelevant 
Authority Just because a famous or powerful person said the statement was true does not make it true, or the other way round just because someone infamous stated something does not make it untrue
Straw manDistracting the audience by arguing against a position which you create specifically to be easy to argue against, rather than the position actually held by those who oppose your point of view. You then appear to win the argument.
Attack the personAttacking the person is irrelevant to the logical consistency or induction
Everyone believes it
(
Tu quoque)
 It must be correct because so many people believe it
Consequences   
Using the consequences of an argument to either support or challenge the argument. It cannot be true because if it was true X would not be true ...
Exploiting problemsExploiting problems in the evidence surrounding an idea to substitute another idea (probably one that cannot be tested and therefore easily criticized).  
Emotionally charged wordsUsing emotionally charged words and ideas to appeal to the audiences emotions rather than their rationality.
Equivocation

Using words with more than one meaning and switching between meaning during the argument.

 
 
3) Denial Arguments
 
 
Denial       
         
Negative evidence    
Arguments that collect and present only supporting evidence while editing out negative evidence 
Personal Incredulity        
Personal argument that states "I don't understand it therefore it cannot be true"
Inconsistency   Applying criteria or rules to one belief, claim, argument, or position but not to others. For example, some consumer advocates argue that we need stronger regulation of prescription drugs to ensure their safety and effectiveness, but at the same time argue that medicinal herbs should be sold with no regulation for either safety or effectiveness.
Moving the Goalposts        
A method of denial by arbitrarily moving the criteria for proof or acceptance out of range of whatever evidence currently exists.
Slippery slopeRejecting an argument because a relatively small first step inevitably leads to a chain of related events culminating in some significant impact
Special Pleading
Special pleading, or ad-hoc reasoning: ad-hoc rejection of negative evidence. For example, one might point out that ESP has never been demonstrated under adequate test conditions, therefore ESP is not a genuine phenomenon. Defenders of ESP have attempted to counter this argument by introducing the arbitrary premise that ESP does not work in the presence of skeptics. 

 
4) Inductive Logic Arguments and Fallacies
 

Inductive Logical Fallacies
 
Events close in time
(Post-hoc ergo propter hoc)
Arguing that because A preceded B, therefore A caused B
Just because A precedes B does not mean that A caused B.
Confusing association with causationAssumes cause and effect for two variables simply because they are correlated. during the 1990s both religious attendance and illegal drug use have been on the rise.  It would be a fallacy to conclude that therefore, religious attendance causes illegal drug use
Small numbers
Drawing conclusions from inadequate sample sizes. For example drawing conclusion from anecdotal evidence or a few instances.
ClustersThe number of cases of disease D in city C is greater than would be expected by chance.  City C has a factory which has released amounts of chemical agent A into the environment. Therefore, agent A causes disease D
This fallacy occurs when someone jumps to the conclusion that a cluster in some data must be the result of a cause. Clusters occur randomly.

Regression to the mean
"Regression to the mean" refers to the tendency of a variable characteristic in a population to move away from the extreme values towards the average value (when chance is part of the mechanism). For instance, we could take a sample of people—it could be just one—measure their heights, and then determine the average height of the sample. This value will be some distance away from the average height of the entire population of people.
Suppose, further, that we take a second sample of the population. If the value for the first sample is an extreme one—that is, far away from the mean—then it is likely that the value of the variable for the second sample will be closer to average than the first one. The farther away from the mean the first sample was, the more likely that the second will be closer to it. This is regression to the mean. 
So if a tall father were to conclude that his tall wife committed adultery because their children were shorter, he would be committing the regression fallacy.         
False ContinuumThe argument appears to demonstrate that two states or conditions cannot be considered distinct (or do not exist at all) because between them there exists a continuum of states. According to the fallacy, differences in quality cannot result from differences in quantity. Example a room is never either "hot" or "cold", because of the continuum of temperatures. The fallacy causes one to erroneously reject a vague claim simply because it is not as precise as one would like it to be. Vagueness alone does not necessarily imply invalidity.
Argument from ignoranceThe fallacy of assuming that something is true/false because it has not been proven false/true. For example: "The student has failed to prove that he didn't cheat on the test, therefore he must have cheated on the test."

 
5) Physical World Tested Arguments
 
 
Prediction    Arguments that make a prediction about the physical world.
TestingArguments that use evidence from experiments and observation
Untested 
Arguments that could, but do not, present evidence from testing
TimeArguments that in theory could be tested but it would take too long
Cost    Arguments that in theory could be tested but the cost is too high

 
 

List of Fallacies

 
 
Comments