18 ORIGIN OF PHYSICAL CONCEPTS 



tions." Again Taine, " Les images sont les 

 exactes reproductions de la sensation." Again 

 Diderot, " Pour imaginer il faut color er un fond 

 et detacher de ce fait des points en leur supposant une 

 couleur differ ente de celle du fond. Eestituez a 

 ces points la mme couleur qu'au fond } a I'instant 

 Us se confondent avec lui et la figure disparait," etc. 

 Again, Dr. Ernest Mach, Vienna, remarks, " We are 

 aware of but one species of elements of Conscious- 

 ness : sensations." " In our perceptions of Space 

 we are dependent on sensations." Dr. Mach 

 repeatedly refers to " space-sensations," and 

 indeed affirms that all sensation is spatial in 

 character. 1 



According to the view of Knowledge of which 

 we have extracted examples above, the ideas of 

 the mind are originally furnished to it by sensation, 

 from which therefore are derived, not necessarily all 

 our Thoughts, but all the materials of Discourse, 

 all that constitutes the essence of Knowledge. 



Our purpose at the moment is to show that this 

 view is altogether false, and our counter proposition 

 is, that it is from our Activity that we derive our 

 fundamental conceptions of the external world ; that 



1 His reason is that we ab origine localise sensations with reference 

 to our organism. This, of course, means by reference to the system 

 of potent energy in which our organism essentially consists. 



