Four-Term Fallacy

Uses a syllogism with four terms instead of three, often because a key term shifts meaning.

Definition

Uses a syllogism with four terms instead of three, often because a key term shifts meaning.

Example

Feathers are light. What is light cannot be dark. Therefore feathers cannot be dark.

Extended explanation

How to think about it:

Uses a syllogism with four terms instead of three, often because a key term shifts meaning. In practice, the key question is whether the conclusion is supported by evidence and logic, or whether it depends on this reasoning shortcut instead.

Related entries

Four-Term Fallacy

How to think about it:

Related by logic, rhetoric, or real-world co-occurrence