SUBJECTIVE CONDITIONS. 25.3 



" mind " itself, as we know not what it is, but if we 

 agree to consider certain physical signs as indices 

 or criteria of mentation, these criteria can be 

 observed. Thus memory is an abstract phenomenon, 

 but by processes of analysis we can determine 

 certain criteria as indices of the property " memory," 

 *md these physical signs can be observed and even 

 experimented upon, thus enabling us to deal by 

 physical processes of inquiry with the faculty 

 *' memory." 



Subjective conditions, pain, joy, fear, etc., can be 

 studied by observing their modes of expression. It 

 is the expression that we can record and analyze. 

 When a child touches a hot teapot his movements 

 and combinations and sequences of movements con- 

 vince us that he felt the heat. An idiot, when he 

 touches the hot teapot, does not move much, may 

 not move at all ; this would be taken as a sign of 

 his mental deficiency. A very strong-minded man of 

 the Spartan type might inhibit the reflex movement 

 stimulated by touch of the hot object. An object 

 impressing by sight, such as a beautiful flower, may 

 inhibit the spontaneous movements of an intelli- 

 gent man. It will not so affect a blind man, and it 

 will produce no effect, present or prospective, on 

 a comatose man ; he is not at all impressionable. 

 Similarly, a deaf man is not stimulated to move- 

 ments or otherwise impressed by sounds, Impres- 

 sionability is one of the expressions of mentation. 



No account of the methods of studying mind 

 can be complete without reference to the processes 

 of thought. Now, "thought" is not a physical 



