The False Subtlety of the Four Syllogistic Figures

Section I

　　General conception of the Nature of Ratiocination [Vernunftschlüsse]

　　A judgment is the comparison of a subject or thing with a predicate or attribute (mark). The comparison is made by using the copula or linking verb "is" or its negative "is not." Therefore, a judgment is a declarative sentence, which is a categorical proposition. Example: The tiger is four-footed. A predicate can also have its own predicate. In the example, the predicate "four-footed" can, itself, have the further predicate "animal." One of these predicates is immediately and directly connected to the subject or thing. The other predicate is mediate and indirectly connected to the subject.

　　"The tiger ----------is---------- a four-footed---------- animal."

　　(Subject)----------(Copula)-----(Immediate Predicate)------(Mediate Predicate)

　　In order to have clear knowledge of the relation between a predicate and a subject, I can consider a predicate to be a mediate predicate. Between this mediate predicate or attribute, I can place an intermediate predicate. For example, in the judgment "the sun is luminous," I attempt a clarification by inserting the predicate "star," which then becomes an immediate predicate, intermediate between the subject "sun" and the mediate predicate "luminous."

　　The sun is a star that is luminous."

　　Sun = subject

　　Is = copula

　　Star = immediate predicate (intermediate predicate) (middle term)

　　Luminous = remote mediate predicate

　　Kant calls this process ratiocination. It is the comparison of a remote, mediate predicate with a subject through the use of an intermediate predicate. The intermediate predicate is called the middle term of a rational inference. The comparison of a subject with a remote, mediate predicate occurs through three judgments:

　　Luminous is a predicate of star;

　　Star is a predicate of sun;

　　Luminous is a predicate of sun (the original judgment).

　　This can be stated as an affirmative ratiocination: Every star is luminous; the sun is a star; consequently the sun is luminous.

　　Note: Kant's examples utilized obscure subjects such a Soul, Spirit, and God and their supposed predicates. These do not facilitate easy comprehension because these subjects are not encountered in everyday experience and consequently their predicates are not evident.

　　Section II - Of the Supreme Rules of all Ratiocination

　　Kant declared that the primary, universal rule of all affirmative ratiocination is: A predicate of a predicate is a predicate of the subject (grammar).

　　The primary, universal rule of all negative ratiocination is: Whatever is inconsistent with the predicate of a subject is inconsistent with the subject.

　　Because proof is possible only through ratiocination, these rules can't be proved. Such a proof would assume the truth of these rules and would therefore be circular. However, it can be shown that these rules are the primary, universal rules of all ratiocination. This can be done by showing that other rules, that were thought to be primary, are based on these rules.