◆ LogicQuest Learn 🎓 Teach 🗺️ Adventure 🤝 Together 🔁 Review ⋯ More ⛶ Focus Teach the Cast Some of LogicQuest’s cast are still learning. When you teach them, YOU learn it best — catch what they get wrong, then quiz them.
✕ Teach Circular-Reasoning Cici You be the teacher — Circular-Reasoning Cici is still learning. Helping Circular-Reasoning Cici figure it out is the practice. (Only for you; nothing is saved.)
Teach the connections
Show how the reasoning tools connect You've helped them one at a time. The real understanding is how the ideas CONNECT — teach that next.
Modus-Ponens Mo (affirm the antecedent: If P then Q; P; therefore Q) × Modus-Tollens Tara (deny the consequent: If P then Q; not-Q; therefore not-P)
Both start from "If it rained, the ground is wet." How can Mo and Tara be the same rule read two ways?
They share one conditional: Mo affirms P to get Q; Tara denies Q to get not-P — forward and backward on the same "if-then" They're unrelated rules that happen to both use "if" Tara only works after Mo has already run
Modus-Ponens Mo then says: “"If it rained, the ground is wet. The ground is wet, so it must have rained." — same rule, right?” — is that right?
No — that affirms the CONSEQUENT (a fallacy); Tara denies it (not-wet → not-rained). Direction matters Right, wet ground proves it rained
The link: one conditional, two valid moves — affirm the "if" (Mo) or deny the "then" (Tara). Reverse either and you get a fallacy.
One "if-then", read forward and backward.
Ad Hominem Hannibal (attacking the arguer instead of the argument) × Tu-Quoque Tessa (deflecting with "you do it too" (hypocrisy charge))
"You say I should recycle, but YOU flew on a plane last week!" — why is Tessa just wearing Hannibal's coat?
Both dodge the claim by attacking the PERSON — Tessa's "you too" is an ad hominem aimed at the arguer's own conduct Tu-quoque is about facts; ad hominem is about feelings — unrelated Tu-quoque actually refutes the argument, ad hominem doesn't
Ad Hominem Hannibal then says: “"He's a hypocrite, so his recycling argument is wrong." That's a fair refutation of the claim.” — is that right?
No — his hypocrisy says nothing about whether recycling helps; that's still attacking the person Right, a hypocrite's argument must be false
The link: tu-quoque is ad hominem's cousin — both swap the argument for the arguer. Naming the family makes both easy to spot.
Attack the claim, never the coat the person is wearing.
Capstone — judge one real argument together A town-hall speech mixes one solid step with two flaws. Bring in the right cast member for each move.
"If we fund the library, kids read more. We're funding it — so kids will read more." Who reasons validly here?
Who do you bring in?
Modus-Ponens Mo — affirm P (funded) → Q (kids read more) Modus-Tollens Tara — deny the consequent False-Dichotomy Fia — only two options
"Don't trust her budget — she flunked math in high school." Who names this flaw?
Who do you bring in?
Ad Hominem Hannibal — attacks the arguer, not the budget Modus-Ponens Mo — valid inference Circular-Reasoning Cici — restates the conclusion
"Either we fund the library OR we give up on our kids." Who names this flaw?
Who do you bring in?
False-Dichotomy Fia — only two options when more exist Modus-Tollens Tara — valid inference Ad Hominem Hannibal — attacks the person
The synthesis: one valid inference plus two fallacies — naming each move's STRUCTURE is what makes you argument-proof.
A good argument survives when you name every move in it.
Try it in the detective tools →
