A comprehensive, structured library of transferable reasoning tools extracted from 34 high-value domains.
This is a collection of reasoning primitives - mental operations that transfer across domains. Not facts, not theories, but thinking tools that remain useful even when specific models are wrong.
Each tool includes:
- What: The core concept
- Why it matters: What problem it solves
- The key move: The actual mental operation
- Classic application: Where it originated
- Surprising application: Evidence it transfers
- Failure modes: When it misleads
- Go deeper: Citations to serious literature
Browse domains/ organized by what you're trying to do:
- Decision Under Uncertainty - Making choices with incomplete information
- Persuasion & Influence - Changing minds and shaping behavior
- Creative Generation - Producing novel ideas and solutions
- Complex System Analysis - Understanding interconnected systems
- Skill Acquisition & Mastery - Learning and developing expertise
- Coordination & Cooperation - Organizing groups and aligning incentives
- Truth-Seeking & Verification - Finding and validating claims
- Conflict & Competition - Strategic interaction and adversarial reasoning
- Resource Allocation - Distributing limited resources optimally
- Pattern Recognition - Identifying structures and making predictions
See tools/glossary.md for a complete alphabetical index of all 523 tools with direct links to their source domains.
See tools/by-tool-name/ for cross-domain tools showing how the same concept appears in different fields.
See tools/by-application/ for problem-oriented guides (e.g., "How to make predictions", "How to diagnose problems").
See matrix.md for the full hybrid matrix showing problem domains × disciplinary approaches.
Decision Under Uncertainty (4):
- Bayesian Statistics - Rigorous framework for updating beliefs with evidence
- Meteorology - Ensemble forecasting, confidence intervals, model averaging
- Intelligence Analysis - Structured analytic techniques, red teaming, hypothesis testing
- Emergency Medicine - Triage protocols, rapid assessment under pressure
Persuasion & Influence (3):
- Game Theory (Signaling) - Costly signals, credible commitments, information revelation
- Social Psychology - Cognitive biases, attitude change, group dynamics
- Classical Rhetoric - Persuasive argumentation, audience analysis, rhetorical appeals
Creative Generation (2):
- Design Thinking - Human-centered problem solving, prototyping, iteration
- Evolutionary Biology - Variation, selection, adaptation, convergent evolution
Complex System Analysis (4):
- System Dynamics - Stock-flow thinking, feedback loops, delays
- Network Science - Graph structure, centrality, clustering, cascades
- Ecology - Niche construction, trophic levels, succession, resilience
- Accident Investigation - Root cause analysis, Swiss cheese model, contributing factors
Skill Acquisition & Mastery (3):
- Learning Theory (Cognitive Science) - Spaced repetition, retrieval practice, transfer
- Sports Science - Deliberate practice, periodization, skill acquisition
- Expertise Studies - Pattern recognition, chunking, mental models
Coordination & Cooperation (3):
- Mechanism Design - Incentive compatibility, revelation principle, implementation
- Organizational Behavior - Team dynamics, culture, motivation, structure
- Constitutional Design - Separation of powers, checks and balances, amendment rules
Truth-Seeking & Verification (4):
- Formal Verification - Proofs, invariants, model checking, specification
- Experimental Design - Controls, randomization, blinding, replication
- Investigative Journalism - Source verification, documentary evidence, corroboration
- Logic & Critical Thinking - Valid inference, fallacy detection, argument analysis
Conflict & Competition (3):
- Military Strategy - Force concentration, interior lines, maneuver warfare
- Competitive Game Theory - Nash equilibrium, minimax, backward induction
- Litigation Strategy - Discovery, burden of proof, adversarial system
Resource Allocation (6):
- Economics - Core - Opportunity cost, marginal analysis, comparative advantage, incentives
- Information Economics - Adverse selection, moral hazard, signaling, mechanism design
- Behavioral Economics - Loss aversion, framing, anchoring, time discounting
- Operations Research - Optimization, queuing theory, linear programming
- Portfolio Management - Diversification, risk-adjusted returns, rebalancing
- Distributive Justice - Fairness principles, allocation criteria, trade-offs
Pattern Recognition (2):
- Machine Learning - Bias-variance tradeoff, regularization, cross-validation
- Medical Diagnostics - Differential diagnosis, base rates, likelihood ratios
| Tool | Domains |
|---|---|
| Base Rate Integration | Logic & Critical Thinking, Medical Diagnostics |
| Pre-mortem Analysis | Intelligence Analysis, Design Thinking, Logic & Critical Thinking |
| Red Team Analysis | Intelligence Analysis, Logic & Critical Thinking |
These tools were extracted separately from each domain's literature, yet converged on the same core mental operation—strong evidence they represent genuine reasoning primitives rather than domain-specific techniques.
Domains were selected using a hybrid matrix approach balancing:
- Breadth: Coverage across disciplinary approaches (formal, empirical, historical, philosophical, creative, practical, contemplative)
- Utility: Coverage across problem domains (decision-making, persuasion, creativity, etc.)
- Extractability: Explicit, documented methodologies with clear literature
Phase 1 focused on high-extractability domains:
- Explicit, documented methodologies
- Clear literature to draw from
- Proven track record of application
- Formalized reasoning techniques
See meta/domain-selection-criteria.md for detailed rationale.
All extractions follow consistent quality criteria:
- Clear mental operations - Not just concepts, but actionable thinking moves
- Evidence of transfer - Surprising applications in different domains
- Honest failure modes - Specific scenarios where tools mislead
- Academic citations - Serious literature, not pop science
See meta/quality-criteria.md for full checklist.
- Start with a problem: "I need to make a decision with incomplete information"
- Find relevant domains: Browse Decision Under Uncertainty
- Learn the tools: Read 1-2 domains that resonate (Bayesian Statistics, Intelligence Analysis)
- Try the key moves: Apply the mental operations to your problem
- Watch for failure modes: Know when the tool misleads
Example workflow:
- Problem: Evaluating a business opportunity with uncertain market demand
- Domains: Bayesian Statistics (base rates, updating), Intelligence Analysis (red teaming), Economics (opportunity cost)
- Key moves: Identify reference class → assign prior → gather evidence → update beliefs → consider alternatives
- Failure modes: Availability bias in selecting reference class, overconfidence after early confirming evidence
- Extraction Template - The prompt used for all extractions
- Quality Criteria - How we evaluate extractions
- Domain Selection - Why these fields
- Extraction Log - Progress tracking
38 additional domains identified for Phase 2 (medium-extractability):
Tacit knowledge traditions:
- Jazz Improvisation - Real-time adaptation, call-and-response, constraint-based creativity
- Carpentry/Woodworking - Material properties, grain direction, tool selection
- Wilderness Tracking - Sign interpretation, inference chains, negative evidence
- Martial Arts (Internal) - Body mechanics, timing, adaptation to opponent
Contemplative practices:
- Buddhist Mindfulness - Attention regulation, non-judgment, impermanence
- Stoicism - Dichotomy of control, negative visualization, voluntary discomfort
- Phenomenology - Bracketing, intentionality, lived experience
Creative domains:
- Photography - Composition, lighting, moment selection
- Screenwriting - Three-act structure, character arcs, conflict escalation
- Film Production - Shot composition, editing rhythm, resource constraints
- Orchestra Conducting - Interpretation, timing, ensemble coordination
Other:
- Epistemology - Justified true belief, coherentism, foundationalism
- Pedagogy - Scaffolding, zone of proximal development, formative assessment
- Forensics - Chain of custody, trace evidence, physical reconstruction
- Sales/Negotiation - BATNA, anchoring, win-win solutions
- Construction Management - Critical path, float, resource leveling
Link Format Compatibility:
- Internal links use GitHub-style anchors (kebab-case slugs, e.g.,
#comparative-advantagefor heading## Comparative Advantage) - These anchors work on GitHub and most markdown renderers, but not Obsidian
- Obsidian uses a different anchor format - links will open the file but not scroll to the section (known incompatibility)
- See tools/glossary.md for a complete alphabetical index of all tools with verified links
This work is licensed under CC BY 4.0. You are free to share and adapt with attribution.
See CONTRIBUTING.md. New domain contributions welcome—follow the extraction template.
If you use these reasoning tools in your work, please cite:
Reasoning Tools Knowledge Base (2025)
Extracted reasoning primitives across 34 domains
Available at: https://github.com/dvdarkin/reasoning-tools
Last Updated: 2025-12-30 Version: 1.3.1 Total Domains: 34 Total Tools: 523 (see glossary for full list) Tools per Domain: 11-23 (average ~15)