of the Evolution Philosophy. 13 



nature of sense-perception. That phenomenon which our 

 minds recognize as sound, science declares to be objectively 

 certain vibrations or waves produced in the atmospheric 

 medium. Between the two orders of phenomena, the ex- 

 ternal fact and the subjective perception of it, there is no 

 relation of identity only one of concomitance. One is 

 subjective, wholly, the other objective; one is mental, 

 the other material. Without an ear, a recipient brain and 

 a conscious mind, the atmospheric vibration might go on 

 forever, and there would be no phenomena of sound. The 

 same principle holds good also in sight. That which to 

 our minds appears as color, externally is the inconceiv- 

 ably rapid vibration of the intangible ether which sur- 

 rounds and penetrates the atmospheric envelope of the 

 globe. Without the eye, the recipient brain, and the subtle 

 synthesis of thought, the phenomenon of vision were 

 impossible.* And so of the other special senses. But what 

 we call matter is inseparable from these sense-perceptions, 

 it is made up of them. Take away what we know as 

 form and weight and color and extension, and nothing 

 material remains. It does not follow, however, that the 

 Unknown Reality which caused in us these sensations has 

 ceased to exist. As firmly as we believe in our own exist- 

 ence, do we believe in that of a Keality external to our- 

 selves, and by precisely the same warrant the unthink- 

 ableness of the contrary proposition. To beings constituted 

 differently from ourselves, however, this reality might pre- 

 sent an appearance totally distinct from that which we 

 know as matter. To the simplest form of organism, for 

 example, whose consciousness is limited to a single undif- 

 ferentiated mode of sense perception, those affections of 

 matter which we know as color, taste, odor, sound, exten- 

 sion, would be wholly incomprehensible. The limitation 

 of our own senses, both in number and in range, is entirely 

 arbitrary.! It is quite conceivable that there may be beings 



Maxwell's new majrnetic theory of light emphasizes still more strongly the 

 principle here laid down. 



tThe president of tlie British Association, Professor Flower, indorses Sir 

 John Lubbock's idea that there may be "fifty other senses as different from 

 ours as sound is from sight ; and even within the boundaries of our own 

 senses there may be endless sounds which we cannot hear, and colors as dif- 

 ferent as red from green of which we have no conception. These and a thou- 

 sand other questions remain for solution. The familiar world which surrounds 

 us may be a totally different place to other animals. To them It may be 

 full of music which we cannot hear, of color which we cannot see, of sensa- 

 tions which we cannot conceive." 



