THE EXPRESSION OF THE EMOTIONS. 437 



repressed by the will, the strictly involuntary muscles retain their ac- 

 tion, and may be highly expressive ; and when, on the other hand, the 

 will is relaxed, the voluntary muscles fail before them. Debility of the 

 brain, Sir C. Bell remarked, is most shown in the case of those muscles 

 which are in their natural condition most under the control of the will. 

 A further mode of expression arises when the checking of one habit- 

 ual movement calls up another. 



" The second principle is that of antithesis. When certain move- 

 ments or gestures have been acquired as aforesaid, and have come to 

 be habitually performed in connection with a certain state of mind, 

 there will then be a strange and involuntary tendency under the op- 

 posite state of mind to directly opposite movements, whether in any 

 way serviceable or not. Hence alone, Mr. Darwin thinks, can be ex- 

 plained, not only the sudden and extreme changes of expression in 

 the attitudes of animals, but many gestures used by savages, or by 

 the deaf and dumb. This antithesis in attitude, from anger and defi- 

 ance to affectionate crouching, is illustrated by him in the case of the 

 dog and the cat, by means of photography. The Cistercian monks, 

 among whom speaking was sinful, invented a gesture language, founded 

 upon the principle of antithesis. It is clear that in this principle the 

 will intervenes largely. 



" Mr. Darwin is, however, less confident in referring expressive 

 signs or gestures to the action of this principle, than to his third origi- 

 nating cause, the direct agency of the nervous system. When the 

 sensorium is strongly excited, nerve-force is generated in great excess, 

 and is transmitted in certain directions, determined by the connection 

 of the nerve-cells, or, where the muscular system is concerned, by the 

 nature of the movements of face or limb, which correspond to each 

 nervous impulse. These are, at the first, at least, independent of the 

 will, or even of habit, though in later stages habit may have consider- 

 able play, inasmuch as nerve-force tends to pass along accustomed 

 channels. Mr. Darwin inclines to think that what seem the most 

 strictly involuntary actions, such as the bristling of the hair in fear or 

 anger, may have been effected by the mysterious power of the will. 

 He is far, however, from laying down dogmatic views upon the opera- 

 tion of these various agencies in causing or varying expression, nor is 

 he prepared to draw sharp lines between the action of his three ele- 

 mentary principles. Many phases or signs of expression may partake, 

 he considers, of all three, and may be referable to no single or direct 

 physiological cause. The visible apparatus of expression may ot 

 course be taken as muscular, and he begins with laying down dia- 

 grams of the various muscles of the face in man, those in particular 



which are connected with the eyes and mouth Suppose we take 



as an illustration the oblique or upturned eyebrows of a man suffering 

 from grief or anxiety. Every one must be familiar, both from Nature 

 and works of art, with the way in which the inner angle of the eye- 



