Understanding Logical Fallacies: Types and Examples
Fallacies
The term “fallacy” refers to an invalid argument or inference. While sometimes used synonymously with “sophistry” (an argument used incorrectly to deceive), a sophistical fallacy is generally more difficult to identify as deceptive. We can distinguish between formal and material fallacies:
- Formal Fallacies: These occur when the inference is incorrect due to the structure of the argument itself, often involving uncertainties and contradictions.
- Material Fallacies: These occur when the error lies in the content of the argument. Several types exist:
1. Fallacies of Relevance
These arguments rely on premises that are not relevant to the conclusion.
1.1. Ad Hominem Fallacy
This common and persuasive fallacy rejects an opinion by criticizing the person holding it, rather than the opinion itself. Example: Dismissing Newton’s philosophy because he once raided a mint.
1.2. Ad Baculum Fallacy (Appeal to Force)
This fallacy defends a thesis or theory not with justification, but by appealing to power or strength. Example: A teacher telling students to study or face harsh punishment.
1.3. Ad Populum Fallacy (Appeal to the People)
Common among journalists and politicians, this fallacy attempts to convince by appealing to emotions and feelings rather than reason. Example: Promoting a product’s quality by associating it with admired celebrities.
1.3.2. Ad Misericordiam Fallacy (Appeal to Pity)
This fallacy uses feelings of sorrow to persuade someone to accept an idea or position. Example: A defense attorney appealing to the jury’s emotions about the defendant’s children instead of proving innocence.
1.4. Ad Verecundiam Fallacy (Appeal to Authority)
This fallacy uses the name of someone with authority in one area to defend an idea or thesis in a different area. Example: Using Darwin’s name to defend a religious idea.
1.5. Ad Ignorantiam Fallacy (Appeal to Ignorance)
This fallacy defends a theory by arguing that it hasn’t been proven otherwise. Example: Claiming ghosts exist because no one has proven they don’t. This does not apply in courts, where someone is innocent until proven guilty.
1.6. Tu Quoque Fallacy (You Also)
This fallacy occurs when someone defends themselves against criticism by responding with another insult or criticism.
1.7. Appeal to Popular Opinion
This fallacy defends an idea by appealing to the fact that everyone agrees with it. Example: Claiming aliens exist because most people believe they do.
2. Fallacies of Insufficient Data
These involve insufficient inductive arguments.
2.1. Inadequate Generalization
This fallacy starts with the fact that some objects or things share a quality and assumes that all share that quality. Example: Assuming that because aspirin is good for headaches, all medication is good.
2.2. Fallacy of Suppressed Evidence
This fallacy consists of concealing unfavorable data to defend a thesis. Example: Displaying high grade rates by removing the records of suspended students.
2.3. Fallacy of False Cause
This fallacy occurs when an accidental relationship is mistaken for a causal one. Example: “I failed this test because it was Tuesday the 13th.”
3. Fallacies of Ambiguity
These fallacies use different meanings of a term within the same reasoning or argument.
3.1. Fallacies of Equivocation
Using different meanings for one word. Example: “The end of a thing is its perfection; death is the end of life; therefore, death is the perfection of life.” The error lies in the word “end,” which first means goal and then finality.
3.2. Fallacy of Amphiboly
This fallacy involves a failure of syntax. Example: “All the kids want to have a car; the Mini is a car; therefore, all the kids want a Mini.” The error is that “a” is first a determinant and then a numeral.
4. Other Fallacies
4.1. Vicious Circle
This fallacy takes the conclusion you want to show as a premise of the argument. Example: “I’m not sick because if I were sick, I wouldn’t eat.”
4.2. Complex Question
This fallacy is committed when someone asks a tricky question that cannot be answered with a simple “yes” or “no” because it implies an unspoken question. Example: A lawyer asking a murderer a loaded question.
4.3. False Dilemma (Black or White Fallacy)
This fallacy occurs when someone fails to recognize a difference between two things because that difference is a matter of degree. Example: Equating a psychopathic murderer with someone who killed another by accident.
4.4. Naturalistic Fallacy
This fallacy derives value judgments from a factual statement. Example: Arguing that because women didn’t vote long ago, they shouldn’t vote now.
4.5. Idealistic Fallacy
This fallacy infers a fact from value judgments. Example: A says that B should be dead, then B dies after A killed B.