CHAPTER VII. 



FALLACIES OF CONFUSION. 



1. UNDER this fifth and last class it is convenient to 

 arrange all those fallacies, in which the source of error is not 

 so much a false estimate of the probative force of known evi- 

 dence, as an indistinct, indefinite, and fluctuating conception 

 of what the evidence is. 



At the head of these stands that multitudinous hody of 

 fallacious reasonings, in which the source of error is the am- 

 biguity of terms : when something which is true if a word be 

 used in a particular sense, is reasoned on 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 error will naturally be 

 oftener committed 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 the senses or to the 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 inductive process as well as the ratiocinative. It 

 occurs in ratiocination in two ways : when the middleterm 

 is ambiguous, or when one of the terms of the syllogism is 

 taken in one sense in the premises, 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 

 regarded as coming under the head of Ambiguous Middle, 

 is (what I believe logical writers mean by ' Fallacia Figurce 



