Week 15: Week 15 — Logical Fallacies
Week of Mon, Dec 14 · week closes Sun, Dec 20
This week's items
Exact due times are in Canvas. Late work accepted at 10% per day; assessed work not accepted late. Vocabulary quizzes are unannounced and cannot be made up.
Know these cold
- A logical fallacy is a flaw in reasoning that makes an argument invalid — even if the conclusion happens to be true, the reasoning that reached it does not hold.
- Ad hominem attacks the person making an argument rather than the argument itself. Disqualifying a claim because of who makes it ignores the quality of the reasoning.
- Straw man misrepresents the opposing position in a weakened or distorted form, then defeats the weakened version rather than the actual argument.
- False dichotomy presents only two options when more options exist — 'Either you support this policy or you support failure' eliminates the middle ground.
- Slippery slope claims that one step will inevitably lead to extreme consequences, without providing evidence for each step in the causal chain.
- Post hoc ergo propter hoc confuses correlation with causation: two events occurring in sequence does not mean the first caused the second.
- Hasty generalization draws a broad conclusion from a small, unrepresentative sample — 'Three students I know prefer lectures, so all students must prefer lectures.'
- Appeal to authority (fallacious) cites an authority outside their area of expertise to support a claim in a different field.
- Bandwagon appeal argues that something is correct because many people believe or do it — popularity does not establish truth.
- Circular reasoning (begging the question) restates the claim as its own evidence: 'This program is effective because it has been shown to work.'
- Red herring introduces an irrelevant issue to distract attention from the actual argument being made.
- Appeal to nature assumes that what is 'natural' is inherently good and what is 'unnatural' is bad — naturalness does not determine value.
Meerk's quiz — open the Week 15 gate
10 questions, no time limit. 85% on your first attempt in a 24-hour window opens the gate. Retakes inside the window are practice — they help you learn, they don't count. Work alone; the point is to know it, not to have seen it.
Dinner Table Question
Ask at home: Is it possible for a flawed argument to reach a true conclusion? Does that matter?
En español: ¿Es posible que un argumento con fallas llegue a una conclusión verdadera? ¿Importa eso?