Deductive Reasoning

Use this skill to test whether a conclusion follows from stated premises, rules, or criteria.

Method Notes

• Deductive reasoning moves from general rules or premises to a specific conclusion.
• A deductive conclusion is only as reliable as the premises and the logic connecting them.
• This method is strongest when rules, definitions, criteria, or constraints are explicit.
• It should separate validity from truth: an argument can be logically valid but built on a false or weak premise.

Required Inputs

Collect or infer these inputs before execution:

• conclusion or decision to test
• stated rules, criteria, principles, policies, or premises
• facts of the specific case
• scope boundary
• exceptions or override conditions

If an input is missing, mark it as missing, state the assumption used, and add a validation action.

When Not To Use

Do not use when there are no clear premises or rules and the task is pattern discovery. Use inductive-reasoning, abductive-reasoning, or affinity-diagram first.

Step-by-Step Execution

Output Template

### 1. Conclusion To Test
- Claim / decision:
- Scope:

### 2. Premise Table
| Premise | Type | Evidence / source | Strength | Scope limit |
|---|---|---|---|---|
|  | rule / criterion / principle / fact / assumption |  | strong / medium / weak / missing |  |

### 3. Logic Chain
1.
2.
3.

### 4. Validity Check
- Does the conclusion follow if the premises are true?
- Weakest premise:
- Exception or edge case:
- Revised conclusion:

Quality Gate

• Do not treat an assumption as a rule.
• Do not hide weak premises inside confident logic.
• Separate logical validity from real-world truth.
• Identify exceptions and scope limits.
• Use plain wording so the conclusion can be challenged or reused.