These circles show that no connection can be established between either group. Using four terms in any syllogism is known as the fallacy of four terms.
(2) A syllogism must have three and only three propositions. The proposition containing the major term is called the major premise, while the one containing the minor term is called the minor premise. In a strictly logical syllogism the major premise is writtenfirst, the minor premise second and the conclusion third. In common parlance, however, the minor premise or even the conclusion may appear first.
The conclusion of a syllogism is always preceded by therefore, or its equivalent, which may be written or understood. The premises always answer the question, Why is the conclusion true? The premises are often preceded by such words as for and because.
The attending irregular syllogisms are arranged logically and the premises and conclusions indicated:
(1a) Illogical.
“You must take an examination because all who enter the school are examined and you, as I understand it, are planning to enter.”
(2a) “Some of these books are not well bound, for they are going to pieces as no well bound book would do.”
(1b) Logical.
All who enter this school are examined, Major premise.
You are planning to enter this school, Minor premise.