Undistributed middle
Undistributed middle
In the categorical syllogism (logic, formal, 5), the middle term must appear in at least one of the two premisses (major and minor) is dtstributed — i.e., as denoting the subject of a proposition A or E, or the predicate of a proposition E or O. Violation of this rule is the fallacy of undistributed middle. A.C.