A Class Room Logic / Deductive and Inductive, with Special Application to the Science and Art of Teaching

by George Hastings McNair

Of the grammatical sentences only the declarative is logical.

The relative clause, though out of place, must be used with the word it modifies.

(7) There are other propositions, though not illogical, to which the logician usually gives some attention. These may be defined as follows:

(1) An analytical proposition is one in which the predicate gives information already implied in the subject.

(2) A synthetic proposition is one in which the predicate gives information not implied in the subject.

(3) A modal proposition is one which states the manner in which the predicate belongs to the subject. The adverbs of time, place, degree and manner are the signs of the modal proposition.

(4) A pure proposition simply states that the predicate belongs or does not belong to the subject.

(5) A truistic or tautologous proposition is one in which the predicate repeats the words and meaning of the subject.

(8) In considering the relation which may exist between subject and predicate, the two terms are employed in extension only, as this use best serves the interests of inference.

The extensional relation between subject and predicate of the four logical propositions may be stated as follows: