Understanding Logical Fallacies

• A logical fallacy is a flawed argument that may seem convincing but lacks logical support.
• Logical fallacies can be committed unintentionally due to poor reasoning or intentionally to manipulate others.
• Recognizing logical fallacies is crucial in your own and others' arguments.

What is a Logical Fallacy?

• A logical fallacy is an error in reasoning where invalid arguments or irrelevant points are presented without supporting evidence.
• Logical fallacies are often used to persuade others, deceptively appearing correct.
• Most logical fallacies consist of premises (statements) and a conclusion, where the premise is meant to support the conclusion.
• Errors in arguments can be factual or logical.
• Factual errors involve incorrect premises that can be disproven with facts.
• Logical fallacies involve premises that do not logically support the conclusion.
• Logical fallacies violate critical thinking principles because the premises don't adequately support the conclusion.

Types of Logical Fallacies

• Logical fallacies can be classified based on psychological reasons or similarity in form.
• Two main types of logical fallacies are informal and formal.

Informal Logical Fallacies

• An informal logical fallacy involves an error in the content of an argument, based on irrelevant or false premises.
• Informal fallacies are grouped by similarity, such as relevance or ambiguity.
• Equivocation is an informal fallacy where the meaning of a word or phrase changes during the argument without being explicitly stated.
• Example of Equivocation: Arguing that all acts are selfish because they satisfy a desire, changing the meaning of "selfish."

Formal Logical Fallacies

• A formal logical fallacy involves an error in the logical structure of an argument.
• Masked-man fallacy is a formal fallacy where the substitution of identical entities leads to a false conclusion due to lack of knowledge.
• Example of Masked-Man Fallacy: Assuming New York citizens know Peter Parker saved the city because they know Spider-Man did, without knowing Spider-Man's identity.

Common Logical Fallacies

• Logical fallacies can occur in various forms of communication, including debates, writing, and internal reasoning.

Red Herring Logical Fallacy

• The red herring fallacy is a deliberate attempt to distract from the main issue by introducing an unrelated topic.
• Example: A politician avoids answering a corruption indictment by talking about unemployment.

Bandwagon Logical Fallacy

• The bandwagon fallacy (or ad populum) argues that something is true because it is popular.
• The argument's validity is based on the number of people who believe something, not on qualified evidence.
• Example: Claiming yoga is the best way to connect with your inner being because more people are starting to believe that.

Straw Man Logical Fallacy

• The straw man fallacy distorts an opponent's argument to make it easier to refute.
• This involves exaggerating or simplifying the original argument to attack a weaker version of it.
• Example: Person 1: "We should legalize marijuana." Person 2: "So you are fine with children taking ecstasy and LSD?".

Slippery Slope Logical Fallacy

• The slippery slope fallacy claims that an initial action will lead to a series of events resulting in a negative outcome without providing evidence.
• Example: Arguing that prohibiting drugs will lead to the government controlling every aspect of our lives.

Hasty Generalization Logical Fallacy

• The hasty generalization fallacy (or jumping to conclusions) draws a conclusion or generalizes a rule based on a small sample or exceptional cases.
• Example: Concluding that smoking isn't that bad based on one person's experience of smoking and living to 95.

Logical Fallacy Examples

False Dilemma

• A false dilemma (or either/or fallacy) presents only two options, ignoring other alternatives, and is often used in advertising.
• Example: An animal testing campaign asks "Who would you rather see live?" presenting only the choice between saving a child or a rat.

Correlation-Causation

• The correlation-causation fallacy (or post hoc) confuses correlation with causation, assuming one thing causes another simply because they occur together.
• Claiming low vitamin D causes multiple sclerosis based on a correlation study, without considering other factors.
• Correlation is a necessary but not sufficient condition for causation.

Frequently Asked Questions about Logical Fallacies

Ad Hominem Fallacy

• Ad hominem is an informal fallacy that attacks a person's character or actions instead of addressing their argument.
• A person's traits are irrelevant to the truth or falsity of their argument.
• Name-calling is an example of ad hominem fallacy.

Appeal to Ignorance Fallacy

• Appeal to ignorance asserts something is true because it hasn't been proven false, or vice versa.
• Also known as the burden of proof fallacy.
• Example: "Unicorns exist because there is no evidence that they don't."

Cognitive Bias vs. Logical Fallacy

• Cognitive bias is a tendency to make decisions illogically due to personal attributes.
• Logical fallacies are mistakes in reasoning that occur when making claims and constructing arguments, disprovable through logic.
• Cognitive bias is an ongoing predisposition, while logical fallacy is an error in reasoning in the moment.