THE AFFERENT PART OF THE NERVOUS SYSTEM 83 



were suddenly, though painlessly, removed. The back- 

 ground of consciousness would be altered; visceral sensa- 

 tion might be likened to the mountain range on the 

 horizon, the constant presence of which would not dis- 

 tract attention from the domestic action in the foreground, 

 though its disappearance would be something uncanny 

 and appalling. 



Sensations are commonly divided into two groups 

 the general and the special. General sensations are those 

 which are referred to the varying conditions of the body 

 itself; special, to causes external to ourselves. Normal 

 visual sensation is clearly of the special class. This is 

 true also of hearing, smell, and taste. (It should hardly 

 be necessary to say that matter in the nasal or mouth 

 cavity is not truly within the body, but only in contact 

 with a portion of its surface.) Sensations from the 

 skin, as pressure, warmth, cold, and cutaneous pain, are 

 conveniently regarded as special, on the theory that 

 something is acting from without to give rise to them. 

 Yet it may be noted that we very readily change our 

 subjective attitude toward some of these experiences. 

 We may say that we are warm or that the room is warm, 

 shifting the reference in the most facile way between the 

 external world and the body itself. 



General sensations are, for the most part, disagreeable, 

 a fact which one is inclined to connect with their common 

 relation to conditions which call for correction. If hunger 

 and thirst were pleasant to experience they would not 

 impel us to take measures for their banishment. Of 

 course, this is true of pain in general, though the remedy 

 may not be so obvious. So largely do the general sensa- 

 tions belong to maladjustments that it has been suggested 

 that the measure of health is to be found in the extent 

 to which they are crowded out by the special. A man who 

 is extremely ill may have little margin for attending to 

 what he sees and hears; bodily discomfort may almost 

 completely monopolize his attention. A man who is ex- 

 ceptionally well has little occasion to dwell on sensations 



