THE PRODUCTION OF MOVEMENT. 373 



In cases where the feeling is strong the law is too famil- 

 iar to require proof. As Prof. Bain says : 



" Each of us knows in our own experience that a sudden shock of 

 feeling is accompanied with movements of the body generally, and with 

 other effects. When no emotion is present, we ai'e quiescent ; a slight 

 feeling is accompanied with slight manifestations ; a more intense shock 

 has a more intense outburst. Every pleasure and every pain, and every 

 mode of emotion, has a definite wave of effects, which our observation 

 makes known to us ; and we apply the knowledge to infer other men's 

 feelings from their outward display. . . . The organs first and promi- 

 nently affected, in the diffused wave of nervous influence, are the mov- 

 ing members, and of these, by preference, the features of the face ( with 

 the ears in animals), whose movements constitute the expression of the 

 countenance. But the influence extends to all the parts of the moving 

 system, voluntary and involuntary ; while an important series of effects 

 are produced on the glands and viscera — the stomach, lungs, heart .kid- 

 neys, skin, together with the sexual and mammary organs. . . . The 

 circumstance is seemingly universal, the proof of it does not require a 

 citation of instances in detail ; on the objectors is thrown the burden of 

 adducing unequivocal exceptions to the law." * 



There are probably no exceptions to the diffusion of 

 every impression through the iwrve-centres. The effect of 

 the wave through the centres may, however, often be to 

 interfere with processes, and to diminish tensions already 

 existing there ; and the outward consequences of such 

 inhibitions may be the arrest of discharges from the 

 inhibited regions and the checking of bodily activities 

 already in process of occurrence. When this happens it 

 probably is like the draining or siphoning of certain chan- 

 nels by currents flowing through others. When, in walk- 

 ing, we suddenly stand still because a sound, sight, smell, or 

 thought catches our attention, something like this occurs. 

 But there are cases of arrest of peripheral activity which 

 depend, not on central inhibition, but on stimulation of 

 centres which discharge outgoing currents of an inhibitory 

 sort. Whenever we are startled, for example, our heart 

 momentarily stops or slows its beating, and then palpitates 

 with accelerated speed. The brief arrest is due to an out- 

 going current down the pneumogastric nerve. This nerve, 

 when stimulated, stops or slows the heart-beats, and this 



* Emotions and Will, pp. 4, 5. 



