502 FALLACIES. 



CHAPTER VII. 



FALLACIES OF CONFUSION. 



§ 1. Under this fifth and last class we find it convenient to arrange 

 all those fallacies, in which the source of error is not so mnch a false 

 estimate of the probative force of known evidence, as an indistinct, in- 

 definite, and fluctuating conception of what the evidence is. 



At the head of these stands that multitudinous body of fallacious 

 reasonings in which the source of error is the ambiguity of terms : when 

 something which is true if a word be used in a particular sense, is rea- 

 soned upon as if it were true in another sense. In such a case there 

 is not a mal-estimation of evidence, because there is not properly any 

 evidence to the point at all ; there is evidence, but to a different point, 

 which, from a confused apprehension of the meaning of the terms used, 

 is supposed to be the same. This en-or will naturally be oftener com- 

 mitted in our ratiocinations than in our direct inductions, because in 

 the former we are deciphering our own or other people's notes, while 

 in the latter we have the things themselves present, either to our senses 

 or to our memory. Except, indeed, when the induction is not from 

 individual cases to a generality, but from generalities to a still higher 

 generalization ; in that case the fallacy of ambiguity may affect the in- 

 ductive process as well as the ratiocinative. It occurs in ratiocination 

 in two ways : when the middle term is ambiguous, or when one of the 

 terms of the syllogism is taken in one sense in the premisses, and in 

 another sense in the conclusion. 



Some good exemplifications of this fallacy are given by Archbishop 

 Whately. " One case," says he, " which may be regar'led as coming 

 imder the head of Ambiguous Middle, is what is called Fallacia 

 Figura: Dictionis, the fallacy built on the grammatical structure of 

 language, from men's usually taking for granted that paronyinous 

 words {i. e. those belonging to each other, as the substantive, adjec- 

 tive, verb, &c., of the same root) have a precisely correspondent 

 meaning, which is by no means universally the case. Such a fallacy 

 could not indeed be even exhibited in strict logical foim, which would 

 preclude even the attempt at it, since it has two middle terms in sound 

 as well as sense ; but nothing is more common in 2:)ractice than to vary 

 continually the terms employed, with a view to grammatical conve- 

 nience ; nor is there anything unfair in such a practice, as long as the 

 meaning is preserved unaltered ; e. g. ' murder should be punished 

 with death; this man is a murderer, therefore he deserves to die,' &c. 

 Here we proceed on the assumption (in this case just) that to commit 

 murder, and to be a murderer, to deserve death, and to be one who 

 ought to die, are, respectively, equivalent expressions ; and it would 

 frequently prove a heavy inconvenience to be debarred this kind of 

 liberty; but the abuse of it gives rise to the Fallacy in question : e.g. 

 projectors are unfit to be trusted ; this man has formed a. project, there- 

 fore he is unfit to be trusted : here the sophist proceeds on the 

 hypothesis that he who forms 2l project must be a projector: whereas 

 the bad sense that commonly attaches to the latter word, is not at all 

 implied in the former. This fallacy may often be considered as lying 



