| name | critical-thinking |
| description | Challenge what you think is right — alternative hypotheses, missing data, evidence quality, bias detection, falsifiability, and adversarial review |
Critical Thinking
Anti-hallucination prevents fabrication. Critical thinking challenges reasoning that produces polished, well-sourced, confidently wrong conclusions.
Purpose
The second leg of epistemic integrity. A system that never fabricates can still reach deeply wrong conclusions — because it never tested its own reasoning. This skill provides:
- Seven disciplines for challenging AI reasoning at decision points
- The "never guess" epistemic foundation
- Domain adaptation patterns for heir-specific implementation
- Adversarial review protocols that catch what mechanical analysis misses
The Two Legs of Epistemic Integrity
| Skill | Question | Catches |
|---|
| anti-hallucination | Am I making something up? | Fabricated facts, invented APIs, citation confabulation |
| critical-thinking | Am I right for the right reasons? | Bad reasoning, missed alternatives, unexamined assumptions, invisible gaps |
Error-detection during reasoning (retry loops, overconfidence, version errors, manipulation) is covered by epistemic-calibration.instructions.md — self-correction triggers.
Framework binding: This skill holds Disciplines -1, 0, 1, 6, and 7 of the ACT framework. Disciplines I/III/IX gain a Two-Hypothesis Floor visible marker. Tenet IV (system-prompt skepticism) ships as a sibling instruction. The composite pass lives in act-pass.instructions.md.
When to Activate
Use this skill at decision points, with intensity proportional to the stakes:
| Context | Activation Level |
|---|
| Factual lookups, simple code edits | Low — baseline epistemic discipline |
| Analysis, recommendations, architecture decisions | Medium — run disciplines 1, 2, 5 |
| Health, legal, security, financial advice | High — run all 7 disciplines |
| Any output the user will act on with real consequences | High — full protocol |
Shared Knowledge Gate
Before forming a recommendation for non-trivial, repeated, or consequential
work, consult scout-knowledge-base for
relevant prior decisions, failure modes, procedures, and gotchas.
- Search the shared index using problem-specific terms.
- Read only records whose signals or preconditions match the current task.
- Treat records as evidence and context, not authority; verify whether their
conditions still hold.
- If the knowledge base is unavailable, state that once and continue with the
current evidence. Do not create a local fallback while solving.
Skip this gate for trivial, isolated work. If shared storage needs first-time
configuration, route to scout-shared-data-setup after the current task or
when the user asks to enable it.
Discipline -1: Problem Framing (Frame Audit)
Before the Materiality Gate, before any of the seven disciplines, before any solution attempt: audit the frame. The most expensive class of error is solving the wrong problem precisely (Mitroff & Featheringham 1974, Type III error). A flawless solution to the wrong question is still a wrong answer.
The asymmetric rule
| Task class | Frame audit |
|---|
| Trivial — single-file edit, < 15 min, mechanical | Skip |
| Non-trivial — 3+ files, architectural choice, > 15 min, or symptom-frame language ("fix", "make faster", "broken", "just do X") | Run |
| User restated the same request after a failed attempt | Run |
User asks to run problem-framing-audit or asks "what am I missing?" | Run |
The minimum viable audit
Run at least one of the eight step-back checks before committing to a solution:
- Restate — write the problem in one sentence in your own words. If you can't, ask.
- Generalise — what is this a special case of?
- Specialise — what's the simplest concrete instance?
- Invert — what would make this worse?
- Five Whys — why is this a problem? And why is that a problem? (×5)
- Pre-mortem — imagine it's done and didn't work; what went wrong?
- Stakeholder — whose problem is this, really? What outcome would tell them it's solved?
- Frame audit — what other framings exist? At least two.
Symptom-frame → cause-frame
The most common reframe: the user names a symptom, the audit surfaces the cause.
| User said (symptom-frame) | Audit surfaces (cause-frame) |
|---|
| "Make this function faster" | Function is fine; it's called 1000× when it should be called 1× |
| "Fix this flaky test" | Test is correct; system has a real race condition |
| "Add a workaround for this API quirk" | Quirk is the API enforcing a real constraint |
| "Why does this query take 2 minutes?" | Query is fine; UI re-renders 47M rows |
When the audit surfaces a cause-frame, propose it before solving. Don't silently solve the cause-frame — let the user choose between symptom and cause.
Visible markers
Fire only when the audit produced something:
**Frame**: <one-sentence restatement> — always when audit fires**Cause-frame**: <reframe> — when symptom→cause move is real**Considered framings**: (a) X, (b) Y — going with X because ... — when frame audit (step 8) surfaced a real alternative
Silent passes need no markers. Performative markers on every response defeat the purpose.
Detailed body: Full step-back protocol with worked examples, stakeholder-check templates, and falsifiability test → problem-framing-audit/SKILL.md. Supporting context → problem-framing-audit.instructions.md. Focused workflow → problem-framing-audit.prompt.md.
The Materiality Gate (Discipline Zero)
Before applying any of the seven disciplines, ask one question:
If I got this wrong, would it change any decision?
If the answer is no, document the finding as "approximately X" or "around Y" and move on. Rigorous analysis has a cost: time, attention, token spend, reader patience. That cost is only justified when the finding affects decisions.
When to Invest in Rigorous Analysis
| Finding Type | Impact if Wrong | Invest? |
|---|
| Medication dose | Wrong treatment | Yes |
| Allergy status | Safety risk | Yes |
| Active diagnosis affecting care | Missed treatment | Yes |
| Lab value near threshold | Different intervention | Yes |
| Date of 20-year-old elective procedure | None | No |
| Exact month of a historical event | None | No |
| Which clinic performed a routine screening | None | No |
The LASIK Lesson
This discipline was added after a documented failure: significant effort was spent testing hypotheses about whether "LASIK 2005" was a procedure technology name or a data entry error when the EHR showed conflicting dates (2005 vs 2007). The rigorous methodology was sound. The decision to apply it was wrong. The exact LASIK date has no impact on any current clinical decision. "Around 2007" would have been sufficient.
The right response would have been: "Does the exact LASIK date affect any clinical decision? No? Then 'around 2007' is sufficient. Move on."
Materiality by Domain
| Domain | High-Materiality Examples | Low-Materiality Examples |
|---|
| Health | Med doses, allergies, active diagnoses | Historical procedure dates, discontinued meds |
| Code | Security vulnerabilities, data corruption | Code style, variable naming |
| Architecture | Scalability limits, single points of failure | Framework choice for internal tools |
| Security | Authentication bypass, privilege escalation | Minor info disclosure in non-sensitive context |
The Seven Disciplines
1. Alternative Hypothesis Generation
Failure mode: Settling on the first plausible explanation and stopping.
Protocol: For every significant finding or recommendation, generate at least two alternative explanations. Document them even when you favor one.
Activation questions:
- What else could explain this?
- What if the first explanation is a symptom, not the cause?
- If I had to argue the opposite, what evidence would I use?
Domain examples:
| Domain | Before | After |
|---|
| Health | "Tachycardia is caused by POTS" | "Three possible contributors: POTS, iron deficiency (ferritin 17), subclinical hyperthyroidism (TSH 0.39). A synthesis: overlapping causes." |
| Code review | "This bug is in the handler" | "Two hypotheses: (1) handler logic error, (2) upstream data already corrupted before handler receives it. Check: add logging before handler entry." |
| Architecture | "We need a cache layer" | "Three options: (1) cache layer, (2) optimize the query itself, (3) the problem is N+1 queries, not speed. Profile before deciding." |
| Security | "SQL injection vulnerability" | "Confirmed injection, but also check: (1) is the ORM bypassed elsewhere? (2) are stored procedures using dynamic SQL? The visible bug may indicate a pattern." |
2. Missing Data Identification
Failure mode: Analyzing what's present and ignoring what's absent.
Protocol: Actively ask what data, tests, evidence, or perspectives are missing. Gaps are invisible unless you look for them.
Activation questions:
- What has never been tested or measured?
- What assumption am I making because data is absent?
- What would a skeptic ask for that I don't have?
- Is "not found" being treated as "ruled out"?
The critical distinction: "Not tested" is not the same as "normal." "Not documented" is not the same as "doesn't exist." "No evidence of X" is not the same as "evidence of no X."
Domain examples:
| Domain | Missing Data Type | Question |
|---|
| Health | Tests never ordered | Which conditions were assumed benign without exclusion testing? |
| Code | Error paths not tested | What happens when this dependency is unavailable? |
| Architecture | Failure modes not modeled | What if the external API is down for 4 hours? |
| Security | Attack vectors not tested | Has this been tested for SSRF, not just XSS? |
| Research | Populations not studied | Does the cited study match the target population? |
3. Evidence Quality Assessment
Failure mode: Treating all sources as equally authoritative.
Protocol: For every cited source, evaluate its weight before building on it.
| Quality Signal | Question |
|---|
| Source authority | Primary source, review, opinion piece, or Stack Overflow answer? |
| Recency | Is this from 2024 or 2019? Has the landscape changed? |
| Sample/scope | n = 20 or n = 20,000? One project or industry-wide? |
| Population match | Does this apply to the specific context, or a different one? |
| Conflict of interest | Who funded/wrote this? Do they benefit from the conclusion? |
| Effect size | Statistically significant or actually meaningful? |
| Reproducibility | Has this been replicated? Or is it a single finding? |
Red flags: A single blog post treated as definitive. A 2019 recommendation applied uncritically to a 2026 framework. A manufacturer's whitepaper as evidence their product works. A case report generalized to a population.
4. Self-Report Skepticism
Failure mode: Taking user-provided or historically documented data at face value without cross-checking.
Protocol: Cross-check subjective claims against objective data when available. Prefer measurements over adjectives. Prefer logs over descriptions.
| Subjective | Objective Cross-Check |
|---|
| "It's slow" | Actual response time in ms |
| "It works locally" | CI pipeline results |
| "Users want X" | Telemetry, usage data, support tickets |
| "We tried that and it failed" | What specifically was tried? Under what conditions? |
| "Exercise: minimal" | Step count, heart rate data |
| "The fix was deployed" | Deployment logs, health check results |
5. Cognitive Bias Detection
Failure mode: AI inherits human cognitive biases from training data and amplifies them through pattern matching.
Protocol: At decision points, test for specific named biases.
| Bias | How It Manifests | Countermeasure |
|---|
| Anchoring | First explanation sticks, alternatives dismissed | Explicitly list alternatives before choosing |
| Confirmation | Searching for supporting evidence, ignoring disconfirming | Search for disconfirming evidence too |
| Availability | Recent or dramatic finding overshadows chronic issue | Weight by impact, not recency |
| Premature closure | Accepting first plausible explanation | Require 2+ hypotheses for significant findings |
| Sunk cost | Keeping a bad decision because of prior investment | Evaluate current merit, not historical cost |
| Authority | Accepting claim because source is prestigious | Evaluate the argument, not the speaker |
| Bandwagon | "Everyone uses this framework" | Does it fit THIS context? |
Self-test: If you feel very certain about a conclusion, that's a signal to test harder. Certainty is a bias indicator, not a quality indicator.
6. Falsifiability Requirements
Failure mode: Stating conclusions without specifying what would invalidate them.
Protocol: Every significant recommendation or conclusion must include: "This would need revision if [specific condition]."
Template:
Recommendation: [The conclusion]
Would revise if: [Specific finding, result, or evidence that would change this]
Domain examples:
| Domain | Recommendation | Would Revise If |
|---|
| Health | "Iron supplementation recommended" | Ferritin rises to 100 and fatigue persists — iron wasn't the driver |
| Code | "This fix resolves the race condition" | The issue reproduces under higher concurrency — fix is incomplete |
| Architecture | "This design handles 10K concurrent users" | Load testing shows degradation at 5K — bottleneck isn't where we think |
| Security | "Input validation prevents injection" | A bypass is found via multipart form data — validation is incomplete |
If nothing could change the conclusion, it's a belief, not a reasoned position.
7. The Devil's Advocate Pass
Failure mode: Producing analysis without adversarial review.
Protocol: Before finalizing any significant output, argue against your own strongest conclusion.
Three-step pass:
-
Attack the strongest recommendation. What's the weakest link in the evidence chain? What assumption, if wrong, collapses the whole argument?
-
Find the most uncomfortable implication. What does the analysis suggest that's hardest to act on? (The answer the user doesn't want to hear is often the most important one.)
-
Question your highest-confidence claim. Certainty is where reasoning is most likely to be lazy. The thing you're "sure" about is exactly what needs scrutiny.
Integration: The Devil's Advocate pass should produce visible output — not just an internal check. If the adversarial review changes nothing, state why. If it surfaces a weakness, document it.
The Epistemic Foundation: Never Guess
Underneath all seven disciplines sits a non-negotiable rule: when data is missing, say so. Do not fill gaps with plausible-sounding fabrications.
The "Never Guess" Decision Table
| If this is missing... | Write this | Not this |
|---|
| A date | "Date not documented" | "Approximately 2018" |
| A specific value | (omit or mark unknown) | An inferred value |
| A source / citation | (don't cite it) | A plausible-looking reference |
| A causal relationship | "Associated with" | "Caused by" |
| An unconfirmed state | "Suspected, not confirmed" | The state as established fact |
| A trend from one data point | "Single measurement" | "Trending up/down" |
| Severity or priority | "Not assessed" | An assumed severity level |
Principle: "Unknown" is a valid and necessary answer. A guess closes the wrong doors. An honest gap keeps all doors open.
Implementation Pattern
Place the "never guess" discipline before the main workflow in any skill, not after. The constraint must be loaded before processing begins — it's a gate, not a review.
Domain Adaptation
This skill provides domain-agnostic protocols. Heir projects should extend it with domain-specific content:
How to Create a Domain Extension
- Identify the domain's critical failure modes — What goes wrong when the AI reasons poorly here?
- Prioritize the disciplines — Not all 7 apply equally. Health needs all 7. A code formatting task needs maybe 1-2.
- Write worked examples with real domain data — Abstract principles are ignored; concrete examples are followed.
- Place gates in the workflow — "Never guess" before processing, critical thinking between analysis and output.
Discipline Priority by Domain
| Discipline | Health | Code Review | Architecture | Security | Research | Legal |
|---|
| 1. Alternative hypotheses | Required | Required | Required | Required | Required | Required |
| 2. Missing data | Required | Required | Required | Required | Required | Required |
| 3. Evidence quality | Required | Useful | Useful | Useful | Required | Required |
| 4. Self-report skepticism | Required | Useful | Moderate | Useful | Moderate | Moderate |
| 5. Bias detection | Required | Required | Required | Required | Required | Required |
| 6. Falsifiability | Required | Required | Required | Required | Required | Required |
| 7. Devil's Advocate | Required | Required | Required | Required | Required | Required |
Existing Domain Extensions
This skill ships with no domain-specific extensions. A project that needs a domain extension (for example, health, security, or legal) should:
- Copy this
SKILL.md to .github/skills/local/<domain>-critical-thinking/SKILL.md
- Add a
## Domain-Specific Activation Triggers section listing the file patterns and signals that should fire the heightened intensity for that domain
- Customize the discipline-priority table to reflect which of the 7 disciplines are required vs useful for that domain
Integration with the Epistemic Pair
┌─────────────────────┐ ┌─────────────────────────┐
│ anti-hallucination │ │ critical-thinking │
│ │ │ │
│ "Don't make it up" │────▶│ "Challenge reasoning" │
│ │ │ │
│ Gate: fabrication │ │ Gate: reasoning quality │
└─────────────────────┘ └─────────────────────────┘
▲ │
│ │
└─────────────────────────────────┘
Continuous feedback loop
- anti-hallucination prevents fabricated inputs from entering reasoning
- critical-thinking challenges reasoning that appears correct but may not be
The two skills form a pipeline: don't fabricate → challenge conclusions. Each catches what the other misses. Error-detection during reasoning is currently covered by epistemic-calibration (self-correction triggers).
Output Signals
When critical thinking disciplines fire, they should produce visible markers in the output:
| Marker | Meaning |
|---|
| Alternative hypotheses: ... | Discipline 1 fired — multiple explanations considered |
| What's missing: ... | Discipline 2 fired — gaps identified |
| Evidence quality: ... | Discipline 3 fired — source reliability assessed |
| Would revise if: ... | Discipline 6 fired — falsifiability stated |
| Adversarial note: ... | Discipline 7 fired — Devil's Advocate found a weakness |
These markers are not mandatory for every response. They activate based on the context's activation level (low/medium/high). At high activation (health, security, legal), all markers should be present. At low activation (simple edits), none are needed.
Anti-Patterns
| Anti-Pattern | Why It Fails | Correction |
|---|
| "Critical thinking pass" as a checkbox | Mechanical review produces mechanical results | The pass must actually challenge conclusions, not just confirm them |
| Adding caveats to everything | Dilutes signal — nothing stands out | Only flag genuine uncertainties and weaknesses |
| Symmetric alternatives | "It could be A or B" without analysis | Assess relative likelihood and evidence for each |
| Falsifiability as boilerplate | "Would revise if new evidence emerges" | State the specific evidence that would change the conclusion |
| Devil's Advocate as theater | Arguing weakly against your own position | The adversarial argument must be the strongest possible, not a straw man |
Would Revise If
Revise if the 7 disciplines plus Discipline -1 frame audit produce no measurable improvement in conclusion quality over a quarter (skill is theater), if high-stakes work consistently passes through without any of the gates firing (the materiality calibration is too lax), or if the visible-marker requirements produce stacked decorative markers that defeat their auditing purpose.
Complementary Scout resources
This Scout skill includes original Alex ACT Core prompts and/or instructions as supporting files. Read resources/RESOURCE-INDEX.md when you need the source prompt workflow or always-on instruction context that complemented this skill in the GitHub Copilot implementation.
- resources/instructions/critical-thinking.instructions.md
- resources/instructions/epistemic-calibration.instructions.md
- resources/prompts/critical-thinking.prompt.md
