CHAPTER I. 

 General Prixciples of Expression. 



The three chief principles stated — The first principle — 

 Serviceable actions become habitual in association 

 with certain states of the mind, and are performed 

 whether or not of service in each particular case — 

 The force of habit — Inheritance — Associated habitual 

 movements in man — Reflex actions — Passage of habits 

 into reflex actions — Associated habitual movements in 

 the lower animals — Concluding- remarks. 



I will begin by giving the three Principles, which 

 appear to me to account for most of the expressions 

 and gestures involuntarily used by man and the lower 

 animals, under the influence of various emotions and 

 sensations. 1 I arrived, however, at these three Prin- 

 ciples only at the close of my observations. They will 

 be discussed in the present and two following chapters 

 in a general manner. Facts observed both with man 

 and the lower animals will here be made use of; but 

 the latter facts are preferable, as less likely to deceive 

 us. In the fourth and fifth chapters, I will describe 

 the special expressions of some of the lower animals; 

 and in the succeeding chapters those of man. Every- 

 one will thus be able to judge for himself, how far my 



1 Mr. Herbert Spencer (' Essays,' Second Series, 1863, 

 p. 138) has drawn a clear distinction between emotions 

 and sensations, the latter being " generated in our cor- 

 poreal framework." He classes as Feelings both emotions 

 and sensations. 



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