304 SENSATION AND THE SENSIFEROUS ORGANS 



It will be observed that the sensiferous wall and 

 the external world are of the same nature ; what- 

 ever it is that constitutes them both is expressible 

 in terms of matter and motion. Whatever changes 

 take place in the sensiferous apparatus are con- 

 tinuous with, and similar to, those which take 

 place in the external world. 1 But, with the sen- 

 sorium, matter and motion come to an end ; while 

 phenomena of another order, or immaterial states 

 of consciousness, make their appearance. How is 

 the relation between the material and the im- 

 material phenomena to be conceived ? This is 



1 The following diagrammatic scheme may help to elucidate 

 the theory of sensation : 



Mediate Knowledge 



+ -^ ^ Immediate 



Sensiferous Apparatus Knowledge 



Objects of Sense I Receptive. Transmissive. Sensificatory 



Btt 



:O 



Sense Organ) (Nerve) (Sensorium) 



Sensations and 

 other States of 

 Consciousness 



Hypothetical Substance of Matter 



Physical World Mental World 



Not Self Self 



Non-Ego or Object Ego or Subject 



Immediate knowledge is confined to states of consciousness, or, 

 in other words, to the phenomena of mind. Knowledge of the 

 physical world, or of one's own body and of objects external to 

 it, is a system of beliefs or judgments based on the sensations. 

 The term "self" is applied not only to the series of mental 

 phenomena which constitute the ego, but to the fragment of the 

 physical world which is their constant concomitant. The cor- 

 poreal self, therefore, is part of the non-ego ; and is objective in 

 relation to the ego as subject. 



