Reconstruct, visualize, and analyze argument structure. Use for: argument reconstruction, premise identification, inference evaluation, finding hidden assumptions, visualizing debates, Toulmin model analysis. Triggers: 'argument structure', 'premises', 'conclusion', 'inference', 'reconstruct', 'map the argument', 'Toulmin', 'argument diagram', 'validity', 'soundness', 'implicit premise', 'hidden assumption', 'logical structure'.
Master the art of reconstructing, visualizing, and evaluating the logical structure of arguments.
Argument mapping serves several purposes:
| Component | Definition | Example |
|---|---|---|
| Conclusion | The claim being argued for |
| "Socrates is mortal" |
| Premise | A reason supporting the conclusion | "All men are mortal" |
| Inference | The logical move from premises to conclusion | "Therefore..." |
| Assumption | Unstated premise needed for validity | (Often hidden) |
P1: [Premise 1]
P2: [Premise 2]
-------------------
C: [Conclusion]
Example:
P1: All men are mortal
P2: Socrates is a man
-------------------
C: Socrates is mortal
Stephen Toulmin's model captures the nuanced structure of real-world arguments.
QUALIFIER
│
▼
GROUNDS ──────────► CLAIM ◄─────────── REBUTTAL
│ ▲ │
│ │ │
▼ │ ▼
WARRANT ◄──────── BACKING (Unless...)
| Component | Definition | Example |
|---|---|---|
| Claim | The conclusion/assertion | "We should ban smoking in restaurants" |
| Grounds | Evidence/data supporting claim | "Secondhand smoke causes cancer" |
| Warrant | Principle connecting grounds to claim | "We should prevent cancer-causing exposures" |
| Backing | Support for the warrant itself | "Preventing harm is a core purpose of public policy" |
| Qualifier | Degree of certainty | "Probably," "Certainly," "Presumably" |
| Rebuttal | Conditions where claim fails | "Unless economic harm outweighs health benefits" |
┌─────────────────────────────────────────────────────────────────────┐
│ │
│ CLAIM: [Central thesis/conclusion] │
│ Qualifier: [Certainly/Probably/Possibly] │
│ │
│ ──────────────────────────────────────────────────────────────── │
│ │
│ GROUNDS: │ REBUTTAL: │
│ [Evidence/facts/data] │ Unless [exception conditions] │
│ │ │
│ ──────────────────────────────────────────────────────────────── │
│ │
│ WARRANT: │
│ [Principle that licenses inference from grounds to claim] │
│ │
│ ──────────────────────────────────────────────────────────────── │
│ │
│ BACKING: │
│ [Support for the warrant] │
│ │
└─────────────────────────────────────────────────────────────────────┘
What is the main claim being defended?
Indicator words: therefore, thus, hence, so, consequently, it follows that, we can conclude
If not explicit: What would the speaker want you to believe/do?
What reasons are given for the conclusion?
Indicator words: because, since, for, given that, as shown by, the reason is
List them: Number each premise explicitly (P1, P2, P3...)
What unstated assumptions are needed for the argument to work?
Test: If we add this premise, does the argument become valid?
Charity: Choose the most reasonable implicit premises
How do the premises relate?
Linked premises: Work together (all needed)
P1 + P2
│
▼
C
Convergent premises: Independent support (each sufficient)
P1 P2
\ /
\ /
C
Serial/Chain arguments: One supports another
P1
│
P2
│
C
┌─────┐
│ P1 │ ← Premise (box)
└──┬──┘
│
▼
┌─────┐
│ C │ ← Conclusion (box)
└─────┘
Linked (all premises needed together):
┌─────┐ ┌─────┐
│ P1 │───│ P2 │
└──┬──┘ └──┬──┘
└────┬────┘
▼
┌─────┐
│ C │
└─────┘
Convergent (independent support):
┌─────┐ ┌─────┐
│ P1 │ │ P2 │
└──┬──┘ └──┬──┘
│ │
└─────┬───────┘
▼
┌─────┐
│ C │
└─────┘
When a premise is itself supported:
┌─────┐
│ P1a │ ← Sub-premise
└──┬──┘
▼
┌─────┐
│ P1 │ ← Intermediate conclusion / Premise for main argument
└──┬──┘
│
┌──┴──┐
│ P2 │
└──┬──┘
▼
┌─────┐
│ C │ ← Main conclusion
└─────┘
┌─────┐
│ P1 │
└──┬──┘
▼
┌─────┐ ┌─────────┐
│ C │ ◄─ ✗ ───│Objection│
└─────┘ └────┬────┘
│
┌────▼────┐
│ Rebuttal│
└─────────┘
For multi-position debates:
THESIS: [Main Position A]
│
├── Support 1: [Argument for A]
│ ├── Evidence 1a
│ └── Evidence 1b
│
├── Support 2: [Another argument for A]
│
└── ANTITHESIS: [Opposing Position B]
│
├── Objection to Support 1: [Why it fails]
│
├── Objection to Support 2: [Why it fails]
│
└── Positive argument for B
│
└── SYNTHESIS: [Higher-level resolution]
│
├── What's preserved from A
├── What's preserved from B
└── What's new
Modus Ponens:
P1: If A, then B
P2: A
---------------
C: B
Modus Tollens:
P1: If A, then B
P2: Not B
---------------
C: Not A
Disjunctive Syllogism:
P1: A or B
P2: Not A
---------------
C: B
Hypothetical Syllogism:
P1: If A, then B
P2: If B, then C
---------------
C: If A, then C
Reductio ad Absurdum:
P1: Assume A (for contradiction)
P2: A leads to contradiction B & not-B
---------------
C: Not A
Generalization:
P1: Sample S has property P
P2: Sample S is representative of population X
---------------
C: (Probably) All X have property P
Analogy:
P1: A has properties F, G, H
P2: B has properties F, G
P3: A has property X
---------------
C: (Probably) B has property X
Inference to Best Explanation:
P1: Phenomenon P is observed
P2: Hypothesis H would explain P
P3: H is the best available explanation
---------------
C: (Probably) H is true
Conceivability Argument:
P1: X is conceivable
P2: If conceivable, then possible
---------------
C: X is possible
Counterexample:
P1: Thesis T claims all X are Y
P2: Case C is X but not Y
---------------
C: Thesis T is false
Thought Experiment:
P1: In scenario S, intuition I is strong
P2: If I is correct, then principle P
---------------
C: Principle P
| Type | Example |
|---|---|
| Empirical | Facts about the world assumed without evidence |
| Normative | Value judgments assumed without defense |
| Conceptual | Definitions assumed without clarification |
| Background | Shared context assumed without statement |
| Scope | Universality assumed without justification |
| Criterion | Question | Assessment |
|---|---|---|
| Validity | Does conclusion follow necessarily? | Yes/No |
| Soundness | Are all premises true? | Yes/No/Unknown |
| Completeness | Are hidden premises stated? | Yes/Partially/No |
| Criterion | Question | Assessment |
|---|---|---|
| Strength | How probable is conclusion given premises? | Strong/Moderate/Weak |
| Cogency | Are premises true AND argument strong? | Yes/No |
| Sample quality | Is evidence representative? | Yes/No |
## Argument Reconstruction: [Topic/Source]
### Conclusion
[State the main claim being argued for]
### Explicit Premises
P1: [First stated premise]
P2: [Second stated premise]
P3: [Third stated premise]
### Hidden Premises
H1: [First unstated assumption needed for validity]
H2: [Second unstated assumption]
### Argument Structure
[Diagram showing how premises relate to conclusion]
### Evaluation
- **Validity**: [Valid/Invalid—explain]
- **Soundness**: [Sound/Unsound/Unknown—explain]
- **Key weakness**: [Most vulnerable point]
### Dialectical Context
[How this argument relates to the broader debate]
## Debate Map: [Topic]
### Question at Issue
[The central question being debated]
### Position A: [Label]
**Thesis**: [Main claim]
**Arguments**:
1. [Argument 1]
- Objection: [Counter]
- Reply: [Response]
2. [Argument 2]
### Position B: [Label]
**Thesis**: [Main claim]
**Arguments**:
1. [Argument 1]
2. [Argument 2]
### Points of Agreement
- [Shared premise 1]
- [Shared premise 2]
### Core Disagreement
[What the debate ultimately turns on]
### Assessment
[Which position is stronger and why]
patterns.md: Comprehensive catalog of argument patternsdiagramming.md: Extended diagramming conventions and tools