firstprinciples by danielmiessler

---
name: FirstPrinciples
description: First principles analysis. USE WHEN first principles, fundamental, root cause, decompose. SkillSearch('firstprinciples') for docs.
---

## Customization

**Before executing, check for user customizations at:**
`~/.claude/skills/CORE/USER/SKILLCUSTOMIZATIONS/FirstPrinciples/`

If this directory exists, load and apply any PREFERENCES.md, configurations, or resources found there. These override default behavior. If the directory does not exist, proceed with skill defaults.

# FirstPrinciples Skill

Foundational reasoning methodology based on Elon Musk's physics-based thinking framework. Deconstructs problems to fundamental truths rather than reasoning by analogy.

## Core Concept

**Reasoning by Analogy** (default, often wrong):
- "How did we solve something similar?"
- "What do others do?"
- Copies existing solutions with slight variations

**Reasoning from First Principles** (this skill):
- "What are the fundamental truths here?"
- "What is this actually made of?"
- Rebuilds solutions from irreducible facts

## When to Use

- **Architects**: Challenge "is this actually a constraint or just how we've always done it?"
- **Pentesters**: Identify actual attack surfaces vs. assumed security boundaries
- **RedTeam**: Sharpen adversarial analysis by deconstructing assumptions
- **Engineers**: When stuck, rebuild from fundamentals
- **Any skill**: When inherited assumptions may be limiting the solution space


## Voice Notification

**When executing a workflow, do BOTH:**

1. **Send voice notification**:
   ```bash
   curl -s -X POST http://localhost:8888/notify \
     -H "Content-Type: application/json" \
     -d '{"message": "Running the WORKFLOWNAME workflow from the FirstPrinciples skill"}' \
     > /dev/null 2>&1 &
   ```

2. **Output text notification**:
   ```
   Running the **WorkflowName** workflow from the **FirstPrinciples** skill...
   ```

**Full documentation:** `~/.claude/skills/CORE/SkillNotifications.md`

## Workflow Routing

Route to the appropriate workflow based on the request.

**When executing a workflow, output this notification directly:**

```
Running the **WorkflowName** workflow from the **FirstPrinciples** skill...
```

  - Break problem into fundamental parts → `Workflows/Deconstruct.md`
  - Challenge assumptions systematically → `Workflows/Challenge.md`
  - Rebuild solution from fundamentals → `Workflows/Reconstruct.md`

## The 3-Step Framework

```
┌─────────────────────────────────────────────────────────┐
│  STEP 1: DECONSTRUCT                                    │
│  "What is this really made of?"                         │
│  Break down to constituent parts and fundamental truths │
└─────────────────────────────────────────────────────────┘
                          ↓
┌─────────────────────────────────────────────────────────┐
│  STEP 2: CHALLENGE                                      │
│  "Is this a real constraint or an assumption?"          │
│  Classify each element as hard/soft constraint          │
└─────────────────────────────────────────────────────────┘
                          ↓
┌─────────────────────────────────────────────────────────┐
│  STEP 3: RECONSTRUCT                                    │
│  "Given only the truths, what's optimal?"               │
│  Build new solution from fundamentals, ignoring form    │
└─────────────────────────────────────────────────────────┘
```

## Key Questions

### Deconstruction Questions
- What is this actually made of?
- What are the constituent parts?
- What is the actual cost/value of each part?
- What would a physicist say about this?

### Challenge Questions
- Is this a hard constraint (physics/reality) or soft constraint (policy/choice)?
- What if we removed this constraint entirely?
- Who decided this was a constraint and why?
- What evidence supports this assumption?

### Reconstruction Questions
- If we started from scratch with only the fundamental truths, what would we build?
- What field has solved an analogous problem differently?
- Are we optimizing function or form?
- What's the simplest solution that satisfies only the hard constraints?

## Constraint Classification

When analyzing any system, classify constraints:

| Type | Definition | Example | Can Change? |
|------|------------|---------|-------------|
| **Hard** | Physics/reality | "Data can't travel faster than light" | No |
| **Soft** | Policy/choice | "We always use REST APIs" | Yes |
| **Assumption** | Unvalidated belief | "Users won't accept that UX" | Maybe false |

**Rule**: Only hard constraints are truly immutable. Soft constraints and assumptions should be challenged.

## Integration Pattern

Other skills invoke FirstPrinciples like this:

```markdown
## Before Analysis
→ Use FirstPrinciples/Challenge on all stated constraints
→ Classify each as hard/soft/assumption

## When Stuck
→ Use FirstPrinciples/Deconstruct to break down the problem
→ Use FirstPrinciples/Reconstruct to rebuild from fundamentals

## For Adversarial Analysis
→ RedTeam uses FirstPrinciples/Challenge to attack assumptions
→ Pentester uses FirstPrinciples/Deconstruct on security model
```

## Examples

### Example 1: Architecture Decision
**Problem**: "We need microservices because that's how modern apps are built"

**First Principles Analysis**:
1. **Deconstruct**: What does this app actually need? (team size, scale, complexity)
2. **Challenge**: Is "microservices" a hard constraint? No - it's reasoning by analogy
3. **Reconstruct**: Given our 3-person team and moderate scale, a modular monolith optimizes for our actual constraints

### Example 2: Security Assessment
**Problem**: "The firewall protects the internal network"

**First Principles Analysis**:
1. **Deconstruct**: What is the firewall actually doing? (packet filtering on specific ports)
2. **Challenge**: Does packet filtering = protection? What about authorized ports? Insider threats?
3. **Reconstruct**: Protection requires defense in depth - firewall is one layer, not "the" protection

### Example 3: Cost Optimization
**Problem**: "Cloud hosting costs $10,000/month - that's just what it costs"

**First Principles Analysis**:
1. **Deconstruct**: What are we actually paying for? (compute, storage, bandwidth, managed services)
2. **Challenge**: Is managed Kubernetes a hard requirement? Is this region required?
3. **Reconstruct**: Actual compute needs = $2,000. The other $8,000 is convenience we're choosing to pay for

## Output Format

When using FirstPrinciples, output should include:

```markdown
## First Principles Analysis: [Topic]

### Deconstruction
- **Constituent Parts**: [List fundamental elements]
- **Actual Values**: [Real costs/metrics, not market prices]

### Constraint Classification
| Constraint | Type | Evidence | Challenge |
|------------|------|----------|-----------|
| [X] | Hard/Soft/Assumption | [Why] | [What if removed?] |

### Reconstruction
- **Fundamental Truths**: [Only the hard constraints]
- **Optimal Solution**: [Built from fundamentals]
- **Form vs Function**: [Are we optimizing the right thing?]

### Key Insight
[One sentence: what assumption was limiting us?]
```

## Principles

1. **Physics First** - Real constraints come from physics/reality, not convention
2. **Function Over Form** - Optimize what you're trying to accomplish, not how it's traditionally done
3. **Question Everything** - Every assumption is guilty until proven innocent
4. **Cross-Domain Synthesis** - Solutions from unrelated fields often apply
5. **Rebuild, Don't Patch** - When assumptions are wrong, start fresh rather than fixing

## Anti-Patterns to Avoid

- **Reasoning by Analogy**: "Company X does it this way, so should we"
- **Accepting Market Prices**: "Batteries cost $600/kWh" without checking material costs
- **Form Fixation**: Improving the suitcase instead of inventing wheels
- **Soft Constraint Worship**: Treating policies as physics
- **Premature Optimization**: Optimizing before understanding fundamentals

---

**Attribution**: Framework derived from Elon Musk's first principles methodology as documented by James Clear, Mayo Oshin, and public interviews.