518 FALLACIES. 



necessarily fall under some one of the heads already enumerated. For the 

 error must be either in those premises which are general propositions, or in 

 those which assert individual facts. In the former case it is an Inductive 

 Fallacy, of one or the other class; in the latter it is a Fallacy of Observa- 

 tion ; unless, in either case, the erroneous premise has been assumed on 

 simple inspection, in which case the fallacy is a priori. Or, finally, the prem- 

 ises, of whichever kind they are, may never have been conceived in so dis- 

 tinct a manner as to produce iiny clear consciousness by what means they 

 were arrived at; as in the case of what is called reasoning in a circle; and 

 then the fallacy is one of Confusion. 



There remain, therefore, as the only class of fallacies having properly 

 their seat in deduction, those in which the premises of the ratiocination do 

 not bear out its conclusion ; the various cases, in short, of vicious argu- 

 mentation, provided against'by the rules of the syllogism. We shall call 

 these. Fallacies of Ratiocination, 



We have thus five distinguishable classes of fallacy, which may be ex- 

 pressed in the following synoptic table : 



^of Simple Inspection 1. Fallacies a priori. 



rlndnctive J 2. Fallacies of Observation. 



from evidence dis- J Fallacies ( 3. Fallacies of Generalization, 



tinctly conceived.. ] Tt^A^ntUra) 



Ueductn e I ^ fallacies of Ratiocination. 

 I- fallacies) 



Fallacies ■> 



'-of Inference ^ 



from evidence indis- ) r tk ^^ • c n e • 



.. ., • 1 r 5. Fallacies of Confusion. 



• tinctly conceived.. > 



§ 3. We must not, however, expect to find that men's actual errors al- 

 ways, or even commonly, fall so unmistakably under some one of these 

 classes, as to be incapable of being referred to any other. Erroneous ar» 

 guments do not admit of such a sharply cut division as valid arguments 

 do. An argument fully stated, with all its steps distinctly set out, in lan- 

 guage not susceptible of misunderstanding, must, if it be erroneous, be so 

 in some one of these five modes unequivocally ; or indeed of the first four, 

 since the fifth, on such a supposition, would vanish. But it is not in the 

 nature of bad reasoning to express itself thus unambiguously. When a 

 sophist, whether he is imposing on himself or attempting to impose on oth- 

 ers, can be constrained to throw his sophistry into so distinct a form, it 

 needs, in a large proportion of cases, no further exposure. 



In all arguments, everywhere but in the schools, some of the links are 

 suppressed ; a fortiori when the arguer either intends to deceive, or is a 

 lame and inexpert thinker, little accustomed to bring his reasoning proc- 

 esses to any test; and it is in those steps of the reasoning which are made 

 in this tacit and half-conscious, or even wholly unconscious manner, that 

 the error oftenest lurks. In order to detect the fallacy, the proposition 

 thus silently assumed must be supplied ; but the reasoner, most likely, has 

 never really asked himself what he was assuming; his confuter, unless per- 

 mitted to extort it from him by the Socratic mode oi interrogation, must 

 himself judge what the suppressed premise ought to be in order to support 

 the conclusion. And hence, in the words of Archbishop Whately, " it must 

 be often a matter of doubt, oi-, rather, of arbitrary choice, not only to which 

 genus each kind of fallacy should be referred, but even to which kind to 

 refer any one individual fallacy ; for since, in any course of argument, one 

 premise is usually suppressed, it frequently happens in the case of a fallacy, 

 that the hearers ai-e left to the alternative of supplying either a premise 



