# Mental Model

> Applies first-principles thinking, inversion, Pareto principle, second-order thinking, and mental frameworks to frame problems.

- Skill: `felipecustodio/mental-model` (Agent Skill, multi-file: 3 files)
- Install (CLI): `npx skillmds@latest add felipecustodio/mental-model`
- Raw SKILL.md: https://api.skillmd.com/api/skills/felipecustodio/mental-model/raw
- Safety review: pending
- Works with: Claude Code, Claude.ai, OpenAI Codex
- Category: AI & ML
- License: MIT
- Author: felipecustodio (https://skillmd.com/u/felipecustodio)
- Updated: 2026-09-17
- Page: https://skillmd.com/skills/felipecustodio/mental-model

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## Overview & Purpose

Mental Model applies established cognitive lenses (First Principles, Inversion, Second-Order Thinking, Occam's Razor, Hanlon's Razor) to break through conventional assumptions and frame complex problems clearly.

## When to Use

- **First Principles**: Deconstructing a problem to fundamental truths.
- **Inversion**: Solving a problem backwards by asking how to guarantee failure.
- **Second-Order Thinking**: Asking "And then what?" to anticipate downstream consequences.

## Execution Workflow

1. **Select Mental Model**: Choose the lens best suited for the challenge (e.g., First Principles or Inversion).
2. **Apply Framework Lens**:
   - *First Principles*: Strip away assumptions; rebuild from fundamental facts.
   - *Inversion*: List everything that causes failure; eliminate those conditions.
   - *Second-Order*: Trace outcomes to 2nd and 3rd order impacts.
3. **Synthesize Insights**: Deriving novel solutions unavailable from conventional thinking.

## Expected Output Contract

```markdown
### Mental Model Application: [Model Name]
- **Core Principle**: [Model Definition]
- **Deconstruction**: [Step-by-step breakdown using the model]
- **Key Insight**: [Actionable conclusion derived from the model]
```

## Scripts

- `scripts/mental_model.py` - Deterministic evaluation, state validation, and CLI tool for mental-model.