Illicit Minor

Alias: Illicit Process of the Minor Term

Form:

Any form of categorical syllogism in which the minor term is distributed in the conclusion but not in the minor premiss.

Example	Counter-Example
All terrorists are extremists. All extremists are radicals. Therefore, all radicals are terrorists.	All whales are mammals. All mammals are animals. Therefore, all animals are whales.

Venn Diagram:

This diagram represents both the Example and Counter-Example. It does not show the conclusion, "All S is P", to be true, which shows that both arguments are invalid.

Exposition:

"Illicit minor" does not refer to underage drinking, but to an illicit process—that is, distribution—of the minor term in a categorical syllogism.

Sibling Fallacy: Illicit Major

Source:

Irving Copi & Carl Cohen, Introduction to Logic (Tenth Edition) (Prentice Hall, 1998), p. 277.