Appetence and Emotion. 385 



dition is more or less variable. In the terms of our previous 

 analogy (Chapter II.) the tissues are "explosive." After a 

 series of explosions have taken place in a tissue, its store 

 of explosive material becomes exhausted, and a powerful 

 stimulus is required to liberate further energy in the 

 exhausted tissue. A period of rest is required to enable 

 the plasmogen to generate a fresh store of explosive 

 material. As this store increases to its maximum pitch, 

 the tissue becomes more and more ready to respond at the 

 slightest touch. Responsiveness to external stimuli is 

 spoken of as sensitiveness; emotional responsiveness is 

 called sensibility. What we have before spoken of as a 

 want or craving is a state of heightened sensibility, which 

 often gives rise to a painful state of general uneasiness. 

 It may also give rise to perceptual representations in 

 memory, as may be seen in the dreams experienced during 

 a state of extreme sexual sensibility. If we seek a basis 

 for the emotional states, therefore, we shall find it in 

 sensibility rather than in pleasure and pain. 



The motor-accompaniments of the emotional states 

 have long been known under the title of the " expression " 

 of the emotions. The term is too deeply rooted to be 

 altered ; but we may notice that what is called the expres- 

 sion of an emotion is really its partial fulfilment in action. 

 Some psychologists, dissatisfied with the term "expression 

 of the emotions," as seeming to imply that the emotion is 

 one thing and its expression another, go so far as to say 

 that the motor-accompaniments are the objective aspect of 

 what, under its subjective aspect, is the emotion. It is 

 quite possible, however, to experience an emotion without 

 any motor-accompaniments at all. Nevertheless, there is, 

 I believe, in such cases an unfulfilled tendency to action. 



A most important feature in general physiology and 

 psychology is the postponement or suppression of action. The 

 physiological faculty on which it is based is inhibition. I 

 do not propose to discuss the somewhat conflicting views 

 on the physiological mechanism of inhibition. It is, how- 

 ever, a fact of far-reaching importance which no one is 



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