ch.t.] THE RELATIVITY OF KNOWLEDGE. 17 



the real things corresponding to the phenomena of redness 

 and resistance, — are in any wise like the phenomena. 



To any one accustomed to examine these matters, such a 

 conclusion seems much like a truism ; amounting, indeed, 

 merely to the statement that we cannot get outside of our 

 own minds. Nevertheless, it will perhaps not be considered 

 a needless prolonging of the argument if I add a few concrete 

 illustrations. 



In the first place, it is extremely probable that the kinds of 

 feeling awakened by the same external cause are not quite 

 alike in any two species of animals. When Wieniawski plays 

 his violin in the Music Hall, his human auditors have 

 awakened in them those feelings which we designate as the 

 consciousness of musical sound ; but if he were to play his 

 violin over a tank containing a number of those mollusks 

 which have no organs of hearing, the feelings awakened in 

 them would be wholly different. They would feel a sort of 

 nervous shiver or jar, like that which our fingers experience 

 when holding a vibrating tuning-fork ; and they would very 

 likely all shrink into their shells. In like manner, the same 

 external agents which arouse well-defined tactual feelings in 

 us, can arouse in a lobster, whose feet and claws are encased 

 in a bony shell, nothing but that vague sort of tactual feeling 

 of which we are conscious when we poke things with a 

 stick. 



In the second place, it is extremely probable that the sub- 

 jective feelings awakened by the same external cause are not 

 quite alike in any two individuals of the same species. In 

 those persons who are troubled with Daltonism, or colour- 

 blindness, luminous undulations so different as those of red 

 and green awaken feelings that are identical. On the other 

 hand, "aerial pulses recurring at the rate of 16 per second, are 

 perceived by some as separate pulses ; but by some they are 

 perceived as a tone of very low pitch. Similarly at the other 

 extreme. Vibrations exceeding 30,000 per second, are in- 



VOL. i. C 



