Thus in ordinary matters our thought turns at once to the conclusion in connection with but one premise.  We make a thousand statements which a moment’s thought will show that we believe because we believe some unexpressed general principle.  If I should say of my dog, “Fido will die sometime,” no sensible person would doubt the truth of the statement.  If asked to prove it, I would say, “Because he is a dog, and all dogs die sometime.”  Thus I apply to a specific proposition, Fido will die, the general one, All dogs die, a proposition about which there is no doubt.

Frequently the suppressed premise is not so well established as in this case, and the belief or nonbelief of the proposition will be determined by the individuals addressed, each in accordance with his experience.  Suppose that in reading we find the statement, “A boy of fourteen ought not to be allowed to choose his own subjects of study, because he will choose all the easy ones and avoid the more difficult though more valuable ones.”  The omitted premise that all boys will choose easy studies, needs to be established by induction.  If a high school principal had noticed that out of five hundred boys, four hundred elected the easy studies, he would admit the truth of the omitted premise, and so of the conclusion.  But if only one hundred had chosen the easy subjects, he would reject the major premise and likewise the conclusion.

It is evident that in order to be sure of the truth of a proposition we must determine the truth of the premises upon which it is based.  An argument therefore is frequently given over wholly to establishing the premises.  If their truth can be demonstrated, the conclusion inevitably follows.

EXERCISES

A. Supply the missing premise for the following:—­

1.  John will succeed because he has a college education. 2.  Henry is happy because he has plenty of money. 3.  Candy is nutritious because it is made of sugar. 4.  These biscuits will make me ill because they are heavy. 5.  This dog must be angry because he is growling. 6.  This fish can swim. 7.  The plural of the German noun der Garten is die Gaerten. 8.  It will hurt to have this tooth filled.

B. Supply the reasons and complete the syllogism for each of the following:—­

1.  This book should not be read. 2.  This hammer is useful. 3.  That dog will bite. 4.  This greyhound can run rapidly. 5.  The leaves have fallen from the trees. 6.  That boy ought to be punished. 7.  It is too early to go nutting. 8.  This boy should not study. 9.  You ought not to vote for this man for mayor.

+Theme XCVIII.+—­Write a paragraph proving the truth of one of the following propositions:—­

1.  Labor-saving machinery is of permanent advantage to mankind.

2.  New Orleans will some day be a greater shipping port than New York.