28 PHYSICAL EXPRESSION. 



research, dependence enough has always been placed 

 upon the truth of the fact that expressions are 

 objective signs of the properties of the subject. If 

 we are certain that the objective signs seen in 

 expression are either uniformly accompanied by 

 certain phenomena, or that the cause of the special 

 hidden phenomenon is the reason of the visible 

 objective sign, in either case we may study the 

 hidden condition by studying the outward objective 

 expression thereof. 



Thus, " mind " in the abstract cannot be submitted 

 to direct physical investigation by experiment, but, 

 if certain physical signs can be shown to be the 

 criteria or expression of mind, we may be able to 

 observe these objective signs, and devise experiments 

 for the elucidation of information with regard to 

 their cause. Again, nutrition of a living organism 

 is a subject of which we understand but little, 

 and what we do know is the result of studying 

 the objective effects of nutrition, and its coinci- 

 dences in other words, the objective expression of 

 nutrition. 



Summary. In this chapter I have endeavoured 

 to explain what is meant in this work by the term 

 " expression," and it is shown that the scope of our 

 subject is wide, dealing with any case where objec- 

 tive physical signs indicate some more hidden phe- 

 nomenon or condition. When a physical sign is 

 a criterion of a condition of the subject, we may 

 investigate that condition "by studying the physical 

 sign. 



The physical sign or expression may be the 



