372 THE SCIENCE OF LOGIC 



new and original premisses (supposed to be admitted by one s 

 adversary) ; but it is usually constructed, in the case of complex 

 dilemmas, by transposing and denying the consequents (in a 

 constructive), or the antecedents (in a destructive dilemma), of the 

 original argument. 



A few examples will illustrate the force of these rules : 



1 I ) If emigrants are useless they are a burden to the colonies ; 

 if they are useful they are a loss to the mother country ; 



But they are either useless or useful ; 



Therefore emigration is either a burden to the colonies or a loss 

 to the mother country. 



Here the hypothetical are not true unless we insert &quot; to the 

 colonies&quot; after &quot;useless&quot; and &quot;at home&quot; after &quot;useful&quot;. But if 

 we read the terms as thus qualified, in the minor, only two out of 

 four possible alternatives are enumerated there. So we ensure 

 the truth of one premiss only by showing the falsity of the 

 other. Thus we &quot; escape between the horns&quot;. 



Or, we might attempt to &quot; rebut&quot; the dilemma thus : 



If emigrants are useless they are no loss to the mother country : 

 if they are useful they are no burden to the colonies. 



But they are either useless or useful. 



Therefore, emigration is either no loss to the mother country or 

 no burden to the colonies. 



This conclusion, however, is quite compatible with the previous 

 one : both alike are incomplete or non-exhaustive : and both 

 dilemmas are equally defective. But the &quot;rebutting&quot; dilemma 

 is sufficiently plausible to disconcert one s adversary by thus arriv 

 ing at an apparently opposite conclusion to his. 



(2) The Athenian mother tried, thus, to dissuade her son from 

 entering public life : 



* If you say what is just men will hate you ; and if you say 

 what is unjust the gods will hate you. 



&quot; But you must say either the one or the other. 



&quot; Therefore you will be hated.&quot; 



To which the son replied : 



&quot; If I say what is just , the gods will love me ; and if I say 

 what is unjust, men will love me. 



&quot; But I must say either. 



&quot; Therefore I shall be loved? 



Again, the conclusions are compatible : the hatred of the gods 

 and the love of men follow from the one alternative (saying what 



