114 THE DOCTRINE OP ENERGY 



whereby we refer to it all the other elements of our 

 sense-experience and conceive of our activity and 

 our whole actual world by reference to the visible 

 sign. It is in consequence of this reference to the 

 visual that bodies are thought of as discrete units, 

 so that it is difficult to conceive that the real thing 

 in virtue of which we experience the perception of, 

 say, a heap of stones, is truly more or less potential 

 Energy just as the continuous process of thought 

 is very different from the disparate symbols of 

 speech. 



I habitually refer to the visual extended image 

 as the primary basis of my idea of the world, or of 

 any particular part of the world, such as my dining- 

 room. Why ? Simply because, for the reasons 

 already noted, the sense of sight is the sense of 

 universal reference. In principle it is the same 

 habitual tendency which makes me associate every 

 element of my world with its appropriate name. 

 It is different in the case of other sensations. When 

 I am absent from Niagara I do not, in thinking of it, 

 primarily conceive of it as a roar of sound. I think 

 of certain motions of mass which, if I were present, 

 would occasion the subjective sensations of sound. 

 But for the habitual tendency arising from the 

 universal reference to the visible I would do the 

 same in the case of the visual image. All I am 



