7 8o THE POPULAR SCIENCE MONTHLY. 



They are afraid without knowing why, perhaps even without knowing 

 that they are afraid, while man, with his highly developed conscious- 

 ness, has a perfect knowledge of his fear. Both man and the brute 

 have in the same degree love of life, dislike of death, and fear in the 

 face of danger. But the notion in the animal is so vague and indis- 

 tinct that it hardly exists ; it is translated by acts the significance of 

 which escapes the actor himself, while in man the same idea becomes 

 precise, reasoned out, and conscious. What we call the instinct for 

 self-preservation is only one of the forms of fear. A violent and irre- 

 sistible emotion takes possession of our whole being when we perceive 

 ourselves in the face of death, and is the manifestation of a love 

 of life and dread of death that every man bears within himself. 

 It requires real courage to do violence to this general and deep 

 instinct. 



We have, therefore, the following progression : The animal, by a 

 simple reflex movement, reacts to excitations that threaten its life ; 

 and this reflex movement is admirably adapted to the necessities of 

 its existence. 



Next the reflex movement becomes more and more complicated, 

 into a movement of the whole with flight, outcry, and tremor. 



Then, as the animal becomes more and more intelligent, emotion 

 accompanies the action, till the animal not only responds to the men- 

 acing excitations by a movement of flight, but has also a conscious 

 feeling of fear. 



Finally, a superior degree of perfection appears in man. Besides 

 the act and the emotion, intelligence is displayed, and the man com- 

 prehends why he is afraid. 



The study of the reactions of the animal shows to what point all 

 the instinctive movements provoked by fright are exactly conformed 

 to the necessity of living, which Nature imposes upon each of her chil- 

 dren. When a danger comes which it is necessary to escape, every 

 animal has two means of deliverance. It can flee precipitately, or it 

 can hide and keep still. I believe that the paralyzing and stupefying 

 action of fear, which is manifested in man as well as in the animal, 

 is a salutary instinct, which is probably transmitted from the ani- 

 mal to man, and which, if it is not useful to man, is evidently quite 

 so to the animal. The reaction of immobility is so complete with 

 some animals as to simulate death. There are various insects which, 

 when they are touched, feign to be dead. Every animal has its 

 special kind of reaction. The butterfly flutters in capricious detours ; 

 the turtle withdraws into its shell ; the bee, surprised by an enemy, 

 stings him ; the cuttle-fish empties its ink-bag ; the hedgehog rolls 

 himself up into a ball ; other animals utter piercing cries. These are 

 all reactions that represent different means of defense. 



In studying the causes of fear, it is well to lay aside all rational 

 and reasoned causes. When we know that our life is threatened, our 



