Which among the following is correct in the context of syllogistic rules.

Correct answer: Syllogistic argument must contain only three terms

• Why this is correct: A categorical syllogism has exactly three terms: the major term, the minor term, and the middle term. If an argument uses more than three distinct terms it commits the fallacy of four terms and cannot be a valid categorical syllogism. Example of a valid three-term syllogism: All M are P; All S are M; therefore All S are P.

• Two negative premises: An argument with two negative premises cannot produce any valid conclusion. Negative premises deny the necessary connection through the middle term. For example, from "No A are B" and "Some C are not B" you cannot validly conclude anything about A and C.

• Distribution rule clarified: The correct rule is that if a term is distributed in the conclusion, it must have been distributed in the premises. It is not required that every term distributed in the premises be distributed in the conclusion. Violating the correct rule results in the illicit process fallacy. Example: "All M are P; All S are M; therefore All P are S" — the conclusion distributes P, but P was not distributed in the premises.

• Middle term distribution: The middle term must be distributed in at least one of the premises. If the middle term is undistributed in both premises, the syllogism commits the fallacy of the undistributed middle. Example of the fallacy: "Some M are P; Some S are M" — M is undistributed in both premises, so no valid conclusion follows.