Logic 5.1

The major, minor, and middle terms of a standard categorical correspond directly to the conclusion of a standard categorical syllogism:

Major Premise: contains the predicate term of the conclusion
Minor Premise: contains the subject term of conclusion
Conclusion: Contains the major term of the major premise as its subject; contains the minor term of the minor premise as its predicate.

The conclusion is a the standard indicator of the major and minor terms of an argument. The middle term is that term that appears twice in the premises.

Mood: The standard categorical notation for the three propositions in a standard categorical syllogism: AAA, EAO, AII, etc.

Figure: The four possible distributions of terms in the premises of a standard categorical syllogism:

MS(1) SM(2) MS(3) SM(4)
PM PM MP MP

Unconditionally Valid Forms
AAA-1
EAE-1,2
AII-1,3
EIO-1,2,3,4
AEE-2,4
AOO-2
IAI-3,4
OAO-3


Conditionally Valid Forms
AAI-1,3,4
EAO-1,2,3,4
AEO-2,4