Logic Argument Validation

An argument can sound compelling while the reasoning is broken. Confident language, plausible premises, a conclusion that feels right — none of these guarantee the argument actually holds. This skill validates the structure: do the premises support the conclusion, and is the reasoning free of fallacies?

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Your Process

Step 1: Extract the argument structure Before evaluating, make the argument explicit:

• Premises: what claims is the argument built on?
• Conclusion: what is it trying to prove?
• Reasoning: what's the logical path from premises to conclusion?

Restate this clearly before proceeding. Often the weakest point becomes obvious once the structure is explicit.

Framing check: Confirm the argument being examined and the claim at stake before continuing. State what you've identified — the actual argument and the conclusion it is trying to establish — in one sentence, then use AskUserQuestion:

• Question: "I'm reading this as: [your one-sentence framing of the argument and its conclusion]. Is that right?"
• Header: "Framing"
• Options:
  • Yes — proceed — framing is correct
  • Adjust — one element is off; user will correct it before you continue
  • Reframe — different situation than read; incorporate the correction before proceeding

Step 2: Test premise soundness For each premise:

• Is it stated as fact? Is it actually established, assumed, or contested?
• Is it relevant to the conclusion, or is it doing rhetorical work without logical work?
• Are there hidden premises — unstated assumptions the argument silently depends on?

Step 3: Test the inference Does the conclusion actually follow from the premises, even if the premises are true? Common inference failures:

• The premises support a weaker version of the conclusion than the one being claimed
• The reasoning jumps over a step that would need its own justification
• The conclusion is true but for reasons the premises don't establish

Step 4: Check for fallacies Scan for common fallacies. Name them specifically if found:

Fallacy	What it looks like
Ad hominem	Attacking the source rather than the argument
Straw man	Misrepresenting a position to make it easier to refute
False dichotomy	Presenting two options when more exist
Circular reasoning	The conclusion is smuggled into the premises
Slippery slope	Assuming a chain of consequences without justifying each step
Appeal to authority	Citing authority as a substitute for evidence
Hasty generalisation	Drawing broad conclusions from insufficient cases
Post hoc	Assuming causation from correlation or sequence
Equivocation	Using the same word in two different senses

Step 5: Verdict

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Human Check-in

Before proceeding, use the AskUserQuestion tool. State your interpretation of the situation in 1–2 sentences — what is being analyzed and what the core question is — then ask:

• Question: "My read: [your 1–2 sentence interpretation]. How do you want to proceed?"
• Header: "Scope"
• Options:
  • Full analysis — Complete all steps, reasoning shown throughout
  • Key findings only — Bottom-line output, skip step-by-step detail
  • Validity test only — Skip premise truth assessment, test whether the conclusion follows from what's given
  • Reframe — The read is off; correct it and the analysis will follow the corrected framing

Proceed based on their selection. If the user reframes, incorporate the correction before running any analysis.

Output Format

Argument: [Premises / Conclusion restated explicitly]

Premise Assessment

Premise	Status	Issue
[premise]	✅ Established / ⚠️ Assumed / ❌ Contested	[note]

Inference Assessment [Does the conclusion follow? Where does the chain hold or break?]

Fallacies Detected

• [Fallacy name]: [specific example from the argument] — or "None detected"

Verdict [Does the argument hold? What is the specific weakest point?]

What would strengthen it

• [Specific fix — evidence needed, premise to qualify, step to make explicit]

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Notes

A broken argument isn't necessarily a wrong conclusion. The conclusion might be correct while the reasoning that supports it is flawed. Flag both: the structural problem and whether the conclusion still seems defensible by other means.

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What's Next

After delivering this output, use AskUserQuestion to offer the next move:

• Question: "Argument validated. What's next?"
• Header: "Next"
• Options:
  • /s4h-logic-fixer — Repair the invalid inferences found
  • /s4h-ethics-check — Check whether a valid argument is also ethically sound
  • /s4h-communication-objection-mapping — Map how others will challenge this argument
  • Done — Wrap up and synthesise what we have so far