236 PHYSICAL EXPKESSION. 



It seems, then, to be acknowledged that what is 

 called instinct is expressed by " movements in 

 aggregation or in succession," due to the congenital 

 or born condition of the nerve-system. If this be 

 the meaning of what is understood by the term 

 " instinct/' we see that instinct may be expressed 

 by combinations and sequences o movements, the 

 direct outcome of the spontaneous action of the 

 central nerve-mechanism as it exists at birth, or in 

 addition by combinations and sequences of reflex 

 actions, and these are in part dependent upon 

 external stimulus. I think the chief notion implied 

 by the term " instinct " is that the movements which 

 express it, whether spontaneous or reflex, are the 

 outcome of the inborn condition of the nerve- 

 centres, and are not acquired ; if they are shown to 

 be acquired I suppose they would be called signs of 

 "mind." We have, then, a more or less arbitrary 

 definition, and a definition proves nothing ; what 

 needs demonstration is that instinct as thus defined 

 does exist as a property or condition of things. 



In our chapter on " Expression of Mind in the 

 Infant " it is assumed that mentation is a function of 

 the brain; we are now concerned with a certain 

 class of mental phenomena called the emotions. 

 The expressions of the emotions have been well 

 described by many observers and authors, and I 

 propose to analyze their descriptions instead of 

 reattempting their task. 



Pain is an emotion, and can be expressed in the 

 body by certain physical signs. "Pain" in the 

 abstract is outside the sphere of objective knowledge, 



