HYPOTHETICAL AND DISJUNCTIVE SYLLOGISMS 371 



in them is easily mistaken for a formal fallacy, whereas it is in 

 fact a material one. 



Firstly, the disjunctive or alternative minor must be exhaustive 

 of the denotation of its subject (143), and of all the possible alterna 

 tives that can arise in the kind of predication made about that 

 subject ; or, if the premiss gives a choice between judgments of 

 independent import and with different subjects (144), all the 

 possible alternative judgments that can be admitted in reference to 

 the given subject-matter must be enumerated. In other words, 

 unless the alternation is complete the premiss must be regarded 

 as false. Whether it is complete or not, must be determined from 

 the subject-matter in each individual case. And it is precisely 

 because it is so easy to allow a possible alternative to pass un 

 noticed and unrecorded, that so many dilemmas are inconclusive. 

 To detect such an alternative is described as escaping between the 

 horns of the dilemma. 



Then, secondly, the conclusiveness of the reasoning will be 

 dependent on the truth of the hypothetical premiss. This must, 

 of course, obey the same rule in regard to complete enumeration 

 of hypotheses as the disjunctive premiss does : for it takes up 

 each alternative and connects this with a certain antecedent or 

 consequent. But, furthermore, the connexion which it establishes 

 in each case between antecedent and consequent must be one of 

 really necessary and universal dependence. In other words, the 

 hypothetical must be taken as necessary, apodeictic, universal, 

 and must as such be true. Here, again, we must determine 

 whether they are true or not, in each separate case, by our 

 acquaintance with their subject-matter. To lay bare the falsity 

 of any portion of the hypothetical premiss, and thus to show 

 that the alleged unpleasant conclusion of the dilemma is not 

 necessarily true is the achievement known as taking the dilemma 

 by the horns} 



A third way of escaping from a dilemma is by &quot; rebutting &quot; 

 it, i.e. by retorting with another dilemma which will appear to 

 prove the contradictory of the previous one. Of course, only 

 really defective dilemmas can be successfully rebutted and not 

 even all these. Very frequently, the conclusion reached by the re 

 butting dilemma is only an apparent contradictory of the original 

 conclusion. The rebutting dilemma may be composed of entirely 



Perhaps the most satisfactory way of dealing with Zeno s argument against 

 motion, as given above. 



24 



