Stephen's Guide to the Logical Fallacies 完全版（PDF）

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Fallacies of Distraction

• False Dilemma: two choices are given when in fact there are three options
  
  


• From Ignorance: because something is not known to be true, it is assumed to be false
  



• Slippery Slope: a series of increasingly unacceptable consequences is drawn
  



• Complex Question: two unrelated points are conjoined as a single proposition
  

Appeals to Motives in Place of Support

• Appeal to Force: the reader is persuaded to agree by force
  



• Appeal to Pity: the reader is persuaded to agree by sympathy
  



• Consequences: the reader is warned of unacceptable consequences
  



• Prejudicial Language: value or moral goodness is attached to believing the author
  



• Popularity: a proposition is argued to be true because it is widely held to be true
  

Changing the Subject

• Attacking the Person:
  

1.     the person's character is attacked

2.     the person's circumstances are noted

3.     the person does not practise what is preached

• Appeal to Authority:
  

1.     the authority is not an expert in the field

2.     experts in the field disagree

3.     the authority was joking, drunk, or in some other way not being serious

• Anonymous Authority: the authority in question is not named
  



• Style Over Substance: the manner in which an argument (or arguer) is presented is felt to affect the truth of the conclusion
  

Inductive Fallacies

• Hasty Generalization: the sample is too small to support an inductive generalization about a population
  



• Unrepresentative Sample: the sample is unrepresentative of the sample as a whole
  



• False Analogy: the two objects or events being compared are relevantly dissimilar
  



• Slothful Induction: the conclusion of a strong inductive argument is denied despite the evidence to the contrary
  



• Fallacy of Exclusion: evidence which would change the outcome of an inductive argument is excluded from consideration
  

Fallacies Involving Statistical Syllogisms

• Accident: a generalization is applied when circumstances suggest that there should be an exception
  



• Converse Accident : an exception is applied in circumstances where a generalization should apply
  

Causal Fallacies

• Post Hoc: because one thing follows another, it is held to cause the other
  



• Joint effect: one thing is held to cause another when in fact they are both the joint effects of an underlying cause
  



• Insignificant: one thing is held to cause another, and it does, but it is insignificant compared to other causes of the effect
  



• Wrong Direction: the direction between cause and effect is reversed
  



• Complex Cause: the cause identified is only a part of the entire cause of the effect
  

Missing the Point

• Begging the Question: the truth of the conclusion is assumed by the premises
  



• Irrelevant Conclusion: an argument in defense of one conclusion instead proves a different conclusion
  



• Straw Man: the author attacks an argument different from (and weaker than) the opposition's best argument
  

Fallacies of Ambiguity

• Equivocation: the same term is used with two different meanings
  



• Amphiboly: the structure of a sentence allows two different interpretations
  



• Accent: the emphasis on a word or phrase suggests a meaning contrary to what the sentence actually says
  

Category Errors

• Composition: because the attributes of the parts of a whole have a certain property, it is argued that the whole has that property
  



• Division: because the whole has a certain property, it is argued that the parts have that property
  

Non Sequitur

• Affirming the Consequent: any argument of the form: If A then B, B, therefore A
  



• Denying the Antecedent: any argument of the form: If A then B, Not A, thus Not B
  



• Inconsistency: asserting that contrary or contradictory statements are both true
  

Syllogistic Errors

• Fallacy of Four Terms: a syllogism has four terms
  



• Undistributed Middle: two separate categories are said to be connected because they share a common property
  



• Illicit Major: the predicate of the conclusion talks about all of something, but the premises only mention some cases of the term in the predicate
  



• Illicit Minor: the subject of the conclusion talks about all of something, but the premises only mention some cases of the term in the subject
  



• Fallacy of Exclusive Premises: a syllogism has two negative premises
  



• Fallacy of Drawing an Affirmative Conclusion From a Negative Premise: as the name implies
  



• Existential Fallacy: a particular conclusion is drawn from universal premises
  

Fallacies of Explanation

·        Subverted Support (The phenomenon being explained doesn't exist)

• Non-support (Evidence for the phenomenon being explained is biased)
  



• Untestability (The theory which explains cannot be tested)
  



• Limited Scope (The theory which explains can only explain one thing)
  



• Limited Depth (The theory which explains does not appeal to underlying causes)
  

Fallacies of Definition

·        Too Broad (The definition includes items which should not be included)

• Too Narrow (The definition does not include all the items which shouls be included)
  



• Failure to Elucidate (The definition is more difficult to understand than the word or concept being defined)
  



• Circular Definition (The definition includes the term being defined as a part of the definition)
  


• 
  

  Conflicting Conditions (The definition is self-contradictory)

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