COMMON BASIS OF EMPIRICISM AND RATIONALISM 35 



tary, it is that attention may be called to the fact, that 'different' 

 here denotes a numerical difference (not a difference in kind) , and 

 that 'distinguishable' accordingly means recognizable as numeri- 

 cally different; while 'separable' refers to the "liberty of the imagi- 

 nation to transpose and change its ideas." Of the three terms, 

 therefore, 'different' applies to the simple ideas as they are in 

 themselves, 'distinguishable' applies to them as objects of atten- 

 tion, and 'separable' applies to them as subject to the caprice of 

 imagination. That the separable is distinguishable, and the dis- 

 tinguishable different, may therefore be regarded as analytical 

 propositions; and Hume rightly regards them as sufficiently 

 proved by the mere challenge to conceive the facts otherwise. 

 But that the different must be distingui hable and the distin- 

 guishable separable are characteristic dogmas of the empiricistic 

 system, proceeding directly from the conception of psychological 

 elements, and thus indirectly (as we have tried to show) from 

 the doctrine of the certainty of immediate experience. Upon 

 this point the following passage in Hume's chapter on memory 

 and imagination is curiously illuminating. "Nor will this liberty 

 of the fancy appear strange, when we consider, that all our ideas 

 are copied from our impressions, and that there are not any two 

 impressions which are perfectly inseparable. Not to mention, that 

 this is an evident consequence of the division of ideas into simple 

 and complex. 111 



We may add that from the logical point of view the psychologi- 

 cal element may be indefinitely complex. That is to say, it may 

 enter into a variety of relations of resemblance, and may be 

 classified accordingly; and in this way it is capable of receiving 

 different predicates and hence of acquiring an extensive meaning. 

 Thus one elementary sound may resemble certain others in pitch, 

 others in duration, and yet others in intensity; and hence may 

 be regarded as a middle C, as a half -note, and as fortissimo. The 

 distinction between these predicates is thus at bottom a distinc- 

 tion between the different relations of resemblance into which 



I 0p. cit.. Book I, Part I, Section 3; our italics. 



