Common Logical Fallacies: Identification and Analysis

Common Logical Fallacies in Argumentation

1. Ad Baculum (Appeal to Force)

This fallacy replaces logical reasoning with intimidation or coercion. Instead of offering evidence, the speaker uses a threat—physical, social, or economic—to compel agreement.

Example: “Approve this project or you will lose your position.” It violates rational debate because persuasion under threat does not prove correctness.

2. Ad Verecundiam (Appeal to Authority)

This fallacy incorrectly bases truth on an authority's statement without evaluating evidence. While expert opinions can inform arguments, they do not replace proof.

Example: “A famous athlete uses this supplement, so it must be safe.”

3. Ambiguity Fallacy

Occurs when vague, double-meaning, or undefined terms mislead or distort reasoning. The speaker exploits uncertainty between meanings.

Example: “He is very liberal with money.” Does that mean he is irresponsible or generous? Clarity in definitions helps avoid this trap.

4. Fallacy of Multiple Questions

A question contains hidden assumptions that presume something unproven.

Example: “When did you stop wasting company funds?” presupposes that a person was wasting company funds.

5. Avoiding the Issue (Red Herring Family)

Instead of addressing the main argument, the speaker diverts to irrelevant or tangential points.

Example: Asked about a scandal, a politician starts talking about economic growth.

6. Ad Hominem (Personal Attack)

Target a person's character, motives, or traits instead of engaging with their argument.

Example: “You can't trust his stand on politics; he dropped out of college.”

7. Casuistry Fallacy

Uses overcomplicated or deceptive logic to justify a questionable act or conclusion. Manipulates moral reasoning to excuse wrong behavior.

Example: Arguing that lying is acceptable because “truth can be harmful.”

8. Red Herring

Introduces an irrelevant topic to distract from the real issue.

Example: “We shouldn't discuss healthcare costs when there are people starving globally.”

9. Pathetic Sophism (Appeal to Pity)

Attempts to persuade by invoking sympathy instead of evidence.

Example: “You must agree with my findings; I worked so hard on this!”

10. Non Sequitur

The conclusion does not logically follow from the premises.

Example: “She owns designer shoes; she must be rich.”

11. Gratuitous Assertion

Asserts a conclusion without support or justification.

Example: “Aliens built the pyramids. Period.”

12. Begging the Question (Petitio Principii)

The conclusion is assumed within the premises; circular reasoning.

Example: “Reading is beneficial because it’s good for you.”

13. Ad Ignoratiam (Appeal to Ignorance)

Claims something is true because it has not been proven false.

Example: “Ghosts must exist; no one has proven they don't.”

14. Hasty Generalization

Draws a broad conclusion from a small sample.

Example: “Two aggressive dogs bit me; therefore, all dogs are dangerous.”

15. Disjunction Fallacy (False Dilemma)

Presents limited choices when alternatives exist.

Example: “Either support this policy, or you hate progress.”

Fallacies Related to General Rules and Parts

16. Accident Fallacy

Applies a general rule to an exceptional case where exceptions actually exist.

Note: The original example was identical to the False Dilemma. A corrected example might be: “Since we should generally tell the truth, it is wrong to lie to a known criminal about where their victim is hiding.”

17. Secundum Quid

Ignores conditions or exceptions that restrict a generalization's application.

Example: “Freedom of speech is absolute, so slander must be legal.”

18. Composition Fallacy

Assumes that what's true for the parts must be true for the whole.

Example: “Every individual note sounds beautiful; therefore, the whole symphony must be perfect.”

19. Continuum Fallacy

Assumes small differences are insignificant, denying meaningful distinctions on a scale.

Example: “Since one gram of sugar isn’t harmful, eating any amount must be fine.”

20. Post Hoc Ergo Propter Hoc (False Cause)

Mistakes correlation or sequence for causation.

Example: “I started wearing this bracelet, and my health improved; the bracelet caused it.”