Thought Experiment Design Skill

Master the art of designing, analyzing, and deploying philosophical thought experiments—the laboratories of the imagination.

What Is a Thought Experiment?

A thought experiment is an imaginative scenario designed to:

• Test philosophical claims against intuitive judgments
• Isolate variables that real-world cases confound
• Reveal hidden assumptions and commitments
• Advance inquiry where empirical evidence is unavailable
• Communicate complex philosophical points vividly

Etymology: German Gedankenexperiment (thought experiment)—originally used in physics (Galileo, Einstein) before becoming central to philosophy.

The Five Elements of a Thought Experiment

Every well-designed thought experiment has:

1. SCENARIO

A clear, precisely specified situation with explicit stipulations.

Good Scenario Properties:

• Conditions clearly stated
• Irrelevant complications removed
• Impossible scenarios made coherently imaginable
• Minimal: only include what's necessary

Bad Scenario Properties:

• Ambiguous conditions
• Unnecessary sci-fi details
• Incoherent combinations
• Kitchen-sink complexity

2. TARGET

The philosophical thesis or intuition being tested.

Examples:

• Zombies → target: physicalism
• Trolley → target: doctrine of double effect
• Gettier → target: JTB analysis of knowledge

3. INTUITION PUMP

The mechanism that generates insight—what reaction does the scenario provoke?

Types of Pumps:

• Elicit strong yes/no judgment
• Create tension between competing intuitions
• Force choice between unpalatable options
• Reveal surprising commitments

4. ISOLATION

Variables controlled and varied to isolate the relevant factor.

Design Questions:

• What factor is being isolated?
• What is held constant?
• What alternative versions test different variables?

5. IMPLICATIONS

What follows from each possible response.

Map the dialectical landscape:

• If you judge X, you're committed to Y
• If you judge not-X, you're committed to Z
• What revisions does each response require?

Thought Experiment Design Process

Step 1: Identify the Target Thesis

What claim do we want to test?

Good targets:

• General philosophical claims ("All X are Y")
• Conceptual analyses ("Knowledge is justified true belief")
• Moral principles ("Always maximize utility")

Poor targets:

• Empirical claims (use science instead)
• Vague intuitions (need to be sharpened first)

Step 2: Find the Pressure Point

Where might intuitions conflict with the thesis?

Strategies:

• Look for edge cases
• Consider extreme applications
• Ask: "What would falsify this?"
• Look for cases where the principle gives counterintuitive results

Step 3: Construct the Scenario

Design a case that cleanly isolates the pressure point.

Design Strategies:

Strategy	Description	Example
Amplification	Push feature to extreme	Zombie (total absence of consciousness)
Isolation	Remove confounding factors	Mary's Room (only color isolated)
Transposition	Move feature to new context	Chinese Room (understanding → symbols)
Reversal	Invert usual arrangement	Inverted qualia
Gradual Series	Create sorites sequence	Neuron replacement
Fission/Fusion	Split or merge entities	Teletransportation fission
Impossible Isolation	Stipulate impossible separation	Zombie (physics without consciousness)

Step 4: Specify Precisely

Remove ambiguities, stipulate relevant facts.

Key Stipulations:

• Physical details (if relevant)
• Mental states (if relevant)
• Temporal sequence
• What the subject knows/doesn't know
• What we (evaluators) are asked to judge

Step 5: Generate Variants

Create alternative versions that probe different aspects.

Variant Types:

• Change one variable at a time
• Create spectrum of cases
• Combine with other thought experiments
• Reverse stipulations

Step 6: Anticipate Responses

Map possible reactions and their implications.

For each response:

• What principle does it express?
• What other cases must you judge similarly?
• What revision does it force on original thesis?

Types of Thought Experiments

Counterexample Generators

Purpose: Refute general claims by finding falsifying instances.

Structure: "If P, then in case C, we'd judge X. But we judge not-X. So not-P."

Examples:

• Gettier cases → refute JTB
• Zombie → refute physicalism
• Frankfurt cases → refute Principle of Alternative Possibilities

Intuition Pumps

Purpose: Evoke strong intuitive judgments that reveal commitments.

Structure: "Consider case C. Clearly, X! So we're committed to P."

Examples:

• Trolley → reveal deontological intuitions
• Experience Machine → reveal anti-hedonist intuitions
• Violinist → reveal pro-choice intuitions

Consistency Tests

Purpose: Reveal hidden commitments by showing what follows.

Structure: "You accept P. P implies Q (shown by case C). So you're committed to Q."

Examples:

• Expanding Circle → show speciesism's arbitrariness
• Veil of Ignorance → show impartiality requirements

Reductio Scenarios

Purpose: Show absurd implications of a view.

Structure: "If P, then in case C, absurd conclusion X. So not-P."

Examples:

• Utility Monster → challenge utilitarianism
• Repugnant Conclusion → challenge total utilitarianism

Bridge Cases

Purpose: Challenge binary distinctions by finding intermediate cases.

Structure: "You distinguish X and Y. But case C is neither clearly X nor Y."

Examples:

• Sorites → vagueness
• Gradual neuron replacement → personal identity

Quality Criteria

Rate thought experiments on these dimensions:

Criterion	Question	Scale
Precision	Are conditions clearly specified?	1-10
Isolation	Does it isolate the target variable cleanly?	1-10
Intuition Strength	Does it provoke clear intuitive responses?	1-10
Resistance	Is it hard to escape the dilemma?	1-10
Significance	Does it matter for important debates?	1-10

Score Interpretation:

• 40-50: Excellent—likely to become classic
• 30-40: Good—useful philosophical tool
• 20-30: Adequate—serves limited purpose
• Below 20: Needs significant revision

Common Pitfalls

1. Begging the Question

Problem: Scenario assumes what's being tested. Example: "Imagine consciousness without neural activity" presupposes dualism. Fix: Stipulate in neutral terms; let the scenario do the work.

2. Science Fiction Creep

Problem: Irrelevant technological details distract. Example: Detailed teleporter mechanism when only the outcome matters. Fix: Minimize to essential features; use "imagine" not "build."

3. Intuition Unreliability

Problem: Strong intuition may be wrong or biased. Example: Intuitions about trolley may reflect mere squeamishness. Fix: Generate variants to test intuition stability; consider error theories.

4. False Precision

Problem: Scenario can't actually be specified clearly. Example: "Imagine a being with partial consciousness." Fix: Acknowledge limits; use multiple variants to triangulate.

5. Ignoring Implications

Problem: Not following through on what responses mean. Example: Judging trolley cases without seeing implications for other cases. Fix: Always map dialectical landscape explicitly.

6. Single-Case Reliance

Problem: Drawing strong conclusions from one scenario. Example: Rejecting utilitarianism based only on Utility Monster. Fix: Generate multiple independent tests; look for convergence.

Analyzing Existing Thought Experiments

Analysis Template

## Analysis: [Name]

### Scenario Summary
[Brief description of the setup]

### Target Thesis
[What philosophical claim it probes]

### The Intuition Pump
[What reaction it's designed to evoke]

### Key Stipulations
1. [Stipulation 1]
2. [Stipulation 2]
3. [Stipulation 3]

### Hidden Assumptions
1. [Assumption 1—often unnoticed]
2. [Assumption 2]

### Space of Responses
| Response | Implication | Proponents |
|----------|-------------|------------|
| [A] | [Implication A] | [Who takes this] |
| [B] | [Implication B] | [Who takes this] |

### Variants Worth Considering
1. What if [change X]?
2. What if [change Y]?

### Assessment
- Strengths: [What it illuminates]
- Weaknesses: [Where it misleads]
- Overall: [How useful is this?]

Creating New Thought Experiments

Output Format

## [EVOCATIVE NAME]: A Thought Experiment

### Scenario
[Precise description with stipulated conditions]

### Key Stipulations
1. [Stipulation 1]
2. [Stipulation 2]
3. [Stipulation 3]

### The Question
[Central philosophical question the scenario poses]

### Target
[What philosophical thesis or intuition this probes]

### Expected Reactions
- **Response A**: [One possible judgment]
  - Implication: If A, then committed to [X]
- **Response B**: [Alternative judgment]
  - Implication: If B, then committed to [Y]

### Variants
| Variant | Change | What It Tests |
|---------|--------|---------------|
| [V1] | [What changes] | [Different variable] |
| [V2] | [What changes] | [Different variable] |

### Dialectical Implications
[What broader conclusions follow from various responses]

Classic Thought Experiments by Domain

Metaphysics

• Ship of Theseus (identity over time)
• Teletransportation (personal identity)
• Swampman (mental content)
• Zombie (consciousness)

Epistemology

• Gettier cases (knowledge analysis)
• Brain in a vat (skepticism)
• Barn facade country (reliability)
• Lottery paradox (probability)

Ethics

• Trolley problem variants (killing vs. letting die)
• Violinist (abortion)
• Experience Machine (hedonism)
• Utility Monster (utilitarianism)

Political Philosophy

• Original Position (justice)
• Drowning Child (obligations)
• Omelas (collective responsibility)

Philosophy of Mind

• Mary's Room (physicalism)
• Chinese Room (AI consciousness)
• What It's Like to Be a Bat (subjectivity)
• Inverted Qualia (functionalism)

For detailed analysis of classics, see classics.md.

Integration with Other Skills

This skill works well with:

• philosophical-analyst: Test positions with thought experiments
• philosophical-generator: Create novel scenarios
• symposiarch: Use as debate prompts
• devils-advocate: Stress-test with edge cases

Reference Files

• classics.md: Detailed analysis of canonical thought experiments
• design_templates.md: Templates and worked examples for creating new experiments