Logic 5.3

Valid syllogisms conform to certain rules, as evidence by Aristotle. There are five rules from the Boolean perspective, and four from the Aristotelian perspective. (The fifth rule does not apply in the Aristotelian perspective, but the first four remain.)

Rule 1: The middle term must be distributed at least once.

Rule 2: If a term is distributed in the conclusion, then it must be distributed in a premise.

Rule 3: Two negative premises is not allowed.

Rule 4: A negative premise requires a negative conclusion, and a negative conclusion requires a negative premise.

Rule 5: If both premises are universal, the conclusion cannot be particular.