HEARING. 57 



colours from each other, and colours which, to general 

 observers, seem of a very opposite kind. As the 

 want of musical ear implies no general defect, in like 

 manner it is to be found in persons who are yet 

 capable of distinguishing with perfect accuracy the 

 form and the greater and less brilliancy of the coloured 

 object ; and we may remark too, in confirmation of 

 the opinion, that the want of musical ear depends 

 on causes not mental but organic ; that, in this 

 analogous case, some attempts, not absolutely un- 

 successful, have been made, to explain the apparent 

 confusion of colours, by certain peculiarities of the 

 external organ of sight. Though the one case, how- 

 ever, were to throw no light upon the other, it is still 

 gratifying to philosophers to have a case at all analo- 

 gous, to which, when they are weary of considering 

 what has baffled all their endeavours to explain it, 

 they may have the comfort of turning away their 

 attention without the mortification of seeming abso- 

 lutely to fly from the subject. Such is the strange 

 constitution of our nature, that merely to have another 

 difficulty presented to us, though it may be yet 

 absolutely insurmountable in itself, if only it have 

 some slight resemblance to a former difficulty, seems 

 to us almost as if we had succeeded in explaining 

 the first ; and each difficulty, by a very convenient 

 transposition which our pride knows well how to make, 

 supplies, according as we have been considering the 

 one rather than the other, the place of explanation to 

 that which is afterwards to explain it no less clearly 

 in its turn. 



" Proceeding on the analogy of these phenomena 

 to those of tickling, an analogy which, striking as it 

 is in many circumstances, does not justify more than 

 conjecture in this application, it may be conceived to 

 be at least not absolutely impossible, since a diversity 

 of some kind there must be, that in those who receive 



