534 



FALLACIES. 



Nothing, perhaps, has contributed 

 more to the error of Realism than 

 inattention to this ambiguity. When 

 several persons are said to have one 

 and the same opinion, thought, or 

 idea, many men, overlooking the true 

 simple statement of the case, which 

 is, that they are aU thinking alike, 

 look for something more abstruse and 

 mystical, and imagine there must be 

 some One Thing, in the primary sense, 

 though not an individual, which is 

 present at once in the mind of each 

 of these persons ; and thence readily 

 sprung Plato's theory of Ideas, each 

 of which was, according to him, one 

 real, eternal object, existing entire 

 and complete in each of the individual 

 objects that are known by one name." 

 It is, indeed, not a matter of infer- 

 ence, but of authentic history, that 

 Plato's doctrine of Ideas, and the 

 Aristotelian doctrine (in this respect 

 similar to the Platonic) of substantial 

 forms and second substances, grew up 

 in the precise way here pointed out, 

 from the supposed necessity of find- 

 ing in things which were said to have 

 the same nature or the same qualities 

 something which was the same in the 

 very sense in which a man is the same 

 as himself. All the idle speculations 

 respecting rb 6v, rb ^v, rb Sfxolov, and 

 similar abstractions, so common in the 

 ancient and in some modern schools 

 of thought, sprang from the same 

 source. The Aristotelian logicians 

 saw, however, one case of the ambi- 

 guity, and provided against it with 

 their peculiar felicity in the invention 

 of technical language, when they dis- 

 tinguished things which differed both 

 specie and numero from those which 

 differed numero tantum, that is, which 

 were exactly alike, ( in some particular 

 respect at least,) but were distinct 

 individuals. An extension of this 

 distinction to the two meanings of 

 the word Same, namely, things which 

 are the same specie tantum, and a 

 thing which is the same numero as 

 well as specie, would have prevented 

 the confusion, which has been a source 

 of so much darkness and such an 



abundance of positive error in meta- 

 physical philosophy. 



One of the most singular examples 

 of the length to which a thinker of 

 eminence may be led away by an am- 

 biguity of language is afforded by 

 this very case. I refer to the famous 

 argument by which Bishop Berkeley 

 flattered himself that he had for ever 

 put an end to "scepticism, atheism, 

 and irreligion," It is briefly as fol- 

 lows : — I thought of a thing yesterday ; 

 I ceased to think of it ; I think of it 

 again to-day. I had, therefore, in 

 my mind yesterday an idea of the 

 object ; I have also an idea of it to- 

 day ; this idea is evidently not another, 

 but the very same idea. Yet an in- 

 tervening time elapsed in which 1 had 

 it not. Where was the idea during 

 this interval? It must have been 

 somewhere ; it did not cease to exist ; 

 otherwise the idea I had yesterday 

 could not be the same idea ; no more 

 than the man I see alive to-day can 

 be the same whom I saw yesterday if 

 the man has died in the meanwhile. 

 Now an idea cannot be conceived to 

 exist anywhere except in a mind ; 

 and hence there must exist an Uni- 

 versal Mind, in which all ideas have 

 their permanent residence during the 

 intervals of their conscious presence 

 in our own minds. 



It is evident that Berkeley here 

 confounded sameness numero with 

 sameness specie, that is, with exact 

 resemblance, and assiimed the former 

 where there was only the latter ; not 

 perceiving that when we say we have 

 the same thought to-day which we 

 had yesterday, we do not mean the 

 same individual thought,but a thought 

 exactly similar ; as we say that we 

 have the same illness which we had 

 last year, meaning only the same sort 

 of illness. 



In one remarkable instance the 

 scientific world was divided into two 

 furiously hostile parties by an am- 

 biguity of language affecting a branch 

 of science which, more completely 

 than most others, enjoys the advan- 

 tage of a precise and well-defined 



