Lesson 2: Common Logical Fallacies

• Distortion: The speaker reshapes an opponent’s position into a weaker version.
• Typical Cue: "They say we should completely overhaul the system, which is absurd."

• Why It Fails: The original claim is never actually addressed, so the rebuttal is irrelevant.

Ad Hominem

• Personal Attack: The argument targets the arguer’s character, motive, or credentials rather than the claim itself.
• Typical Cue: "You’re too young to understand economics."

• Why It Fails: Truth is independent of who says it; attacking the person does not refute the premise.

Slippery Slope

• Chain Reaction Claim: One action is said to inevitably trigger a cascade of negative outcomes.
• Typical Cue: "If we allow this exception, soon every rule will be ignored."

• Why It Fails: The causal link is assumed, not demonstrated.

False Dilemma

• Limited Options: The speaker presents only two alternatives, ignoring viable middle ground.
• Typical Cue: "Either we ban all plastics, or the planet is doomed."

• Why It Fails: Reality often offers a spectrum of solutions.

Appeal to Authority

• Expert Reliance: The argument leans on a respected figure’s opinion without scrutinizing the evidence.
• Typical Cue: "Dr. X says this policy works, so it must be effective."

• Why It Fails: Authorities can be mistaken; arguments need supporting data.

Circular Reasoning - Self‑Referencing: The conclusion is restated as a premise.

• Typical Cue: "We must trust the law because it is law."

• Why It Fails: No new information is offered; the argument goes nowhere. >

Strategies to Avoid Fallacies

• Pause & Verify: Before responding, confirm the opponent’s actual wording.
• Ask Clarifying Questions: "Can you elaborate on what you meant by…?"

• Focus on Evidence: Anchor rebuttals in data, not rhetoric.

• Map the Argument: Sketch premises and conclusions to spot hidden jumps.

Quick Review

• Straw Man: Misrepresent.

• Ad Hominem: Attack the person.

• Slippery Slope: Unwarranted cascade.

• False Dilemma: Only two options.

• Appeal to Authority: Rely on prestige.

• Circular Reasoning: Reason repeats itself. By internalizing these patterns, debaters can both safeguard their own reasoning and dismantle flawed arguments with confidence.