An Introduction to Clearer Thinking
consists of three statements, as follows:
a) Major premise: All cows are females.
b) Minor premise: Bessie is a cow.
c) Conclusion: Bessie is a female.
...The following kinds of syllogism will be discussed: (1)
categorical, (2) conditional, (3) alternative, and (4) disjunc
tive.
- The categorical syllogism is so called because each of
its statements is categorical, or absolute, with no “ifs” or
other limitations. Understanding the principles of valid
reasoning in the categorical syllogism requires a knowledge
of the parts of the syllogism— their names, their aspects, and
their functions.
(a) Term: Each of the things named in the syllogism. In
the syllogism about Bessie the cow, the terms are cows,
females, and Bessie. Every categorical syllogism has three
terms: the major term (the term in the predicate of the
conclusion), the minor term (the term in the subject of the
conclusion), and the middle term (the term that appears in
both premises but not in the conclusion).
(b) Class: Each term refers to (or names) a group whose
members share certain characteristics. Cows are a class;
females are a class; Bessie is a class—this time a class with
but one member, or “a class of one.”
(c) Statement: A subject-predicate assertion; every syllo
gism contains three. Each statement contains two terms: one
the subject of the statement, the other the predicate-comple-
ment of the statement. The two terms are linked by a verb,
usually a state-of-being verb like is or are. When some other
verb appears, the statement usually can be translated into an
is or are statement; for example, if we assert that “All cows
give milk,” we must understand that milk is not a term in the
statement, but milk-giving animals is the correct term, and
we translate the statement as, “All cows are milk-giving
animals.” Statements in the syllogism do not imply equality.
“All cows are females” does not assert that cows equal
females; it asserts, rather, that the class called cows is
included in the class called females. Syllogistic statements
include or exclude; they do not equate.
