fear is easily explained as the result of the knowledge. A man who is bound to the mouth of a cannon experiences a very strong fear; but, though legitimate, it is not a natural fear in the zoölogical sense of the word. He is in fear because he knows that his life is in danger; but this is a thought-out fear, reasoned and intelligent. Man's rational fears are the fear of death, the fear of pain, and the dread of disesteem. To the fear of death are ultimately referable all emotions of fear, whether conscious or not. Pain is a motive for dread even when it is not mortal, as, for example, in the case of a patient who is awaiting a surgical operation. A more curious kind of rational fear is the fear of disesteem, which is felt by the orator about to make his address, or the actor of any kind to perform his part before the public. It can be assimilated, I think, to the dread that is felt by the patient about to undergo an operation, but is aggravated by the circumstance that, while the patient has only to be passive, the actor knows that the judgment of his audience will depend on himself. In a milder form, it is timidity, such as is shown by young people still unused to society. We shall not enter into the psychological history of these moral fears, interesting as it might be. Nor shall we dwell upon the terror which is determined by the thought of danger and threatened death, for those feelings do not explain the origin of fear. Only the unthought fears can aid in that research.
There is a peculiar feeling, which does not seem identical with fear, though it is of the same character, which may be described as the vertigo of height. It is brought on by the view of a great depth. There is nothing rational in it, for there is no more danger of falling from a great height than from a slight elevation; and a slight barrier, even too slight to afford any real protection, is often sufficient to remove it. But it serves a protective purpose, in guarding us against the perils of elevated places. It is an excellent example of the psychical reflex affection, embodying all of its conditions of being involuntary, conscious, dependent on the sense of sight, and variable with different persons; and it is easily modifiable by education and habit.
The emotion excited by a sudden, violent noise is analogous to fear. It might be described simply as a rudiment of fear; a physical disturbance, or a visceral emotion, producing a momentary response in the mind. Many persons, for instance, are afraid of the sound of thunder. The noise of the storm tends to heighten the effect; and it is likewise observable in animals which, in tropical countries, show great distress during earthquakes and storms, and are also peculiarly sensitive to strident noises.
A loud noise, even when it is not unexpected, always causes a kind of surprise, which is manifested by winking and a general thrill, with palpitation of the heart. During the exposition of 1878 I watched the movements of parties of visitors who stopped to observe the operation
