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

by George Hastings McNair

This complex dilemma is valid since the minor premise denies the two consequents.

17. ORDINARY EXPERIENCES RELATED TO THE DISJUNCTIVE PROPOSITION AND HYPOTHETICAL ARGUMENT.

(1) One desires to take a certain trip which involves various routes; information from time tables reveals the fact that there are three routes A, B, and C. Concerning the conditions of the journey the most important factor is the matter of comfort. Further investigation makes evident that route B will be the most comfortable one, and consequently is the route selected. Putting this ordinary experience in argumentative form gives the following:

The route is to be either A, or B, or C;

I will take route A; if it is the most comfortable; (co-extensive)

A is not the most comfortable route,

Hence I will not take route A.

If B is the most comfortable route, I will take it;

B is the most comfortable route,

Hence I will take route B.