ORIGIN OF PHYSICAL CONCEPTS 35 



abstractive suggestion is less pronounced ; till in 

 the person of Justice Shallow it vanishes in the 

 very concrete. 



Behind and beneath all these considerations we 

 should never lose sight of the great main facts that 

 thought is an activity ; that its function therefore 

 is to represent or reproduce our pure exertional 

 activity ; that such representation is at the basis 

 of all our concepts of externality ; that sensation 

 per se is mere interruption of activity ; that per 

 se it possesses no spatial or extensive or external 

 suggestiveness ; that sensations nevertheless serve 

 to denote or give feature and particularity to our 

 experience of activity ; that all perception of 

 the external is at bottom therefore a mental 

 /representation of exertional activity and its forms, 

 / denoted, punctuated, identified by sensation, which 

 latter by itself, we repeat, carries no suggestion of 

 externality. This view revolutionises the whole 

 psychology of Perception, and therefore, though 

 it at once gives to that science a much-needed unity, 

 clarity, and simplicity, it will naturally be accepted 

 with reluctance by the laborious authors of the 

 cumbrous theories still generally current. 



