SOME CURIOSITIES OF THINKING. 735 



ly absurd, is the outcome of a process of reasoning starting from a 

 premise, which premise is an absurd fear or doubt. There is noth- 

 ing wrong in the act or in the process of logical conclusion, grant- 

 ing the premise. The premise is, however, a false idea forced 

 upon the consciousness so intensely as to carry conviction. It is 

 quite analogous to a hallucination in the domain of sensory per- 

 ception, but it belongs to the ideational sphere, or to the emotional 

 sphere of mind. You will have noticed that the same sort of 

 doubts occur to different minds. 



It may be said that such fears, doubts, or impulses might occur 

 to any one, but could be at once discarded. In the fact that they 

 are not discarded, that there is a lack of self-control and mental 

 balance which allows of their taking possession of the mind, lies 

 the proof that in such cases there is a defect of mental develop- 

 ment. Such cases show us clearly how important it is to sound 

 normal mental action that a firm control over the tendencies of 

 the mind to wander foolishly, to indulge in absurd doubts and 

 fears, should be constantly exercised ; and such control should be 

 inculcated upon the child's mind as it develops, lest the individ- 

 ual come to yield to or to foolishly fear these abnormal impulses. 

 That self-control is the highest quality of mind is evident from 

 the fact that the first evidence of mental deterioration is seen in 

 a beginning failure of this power. 



You are all familiar with the fact that many acts of an insane 

 kind are spontaneous, and not the result of a process of logical 

 reasoning. Thus, a sudden impulse to steal, or to set fire to an 

 object, may come upon one and lead to the act, for which no expla- 

 nation can be given except the sudden onset of an abnormal and 

 irresistible desire. These acts are in a way as unexpected as the 

 hallucinations or the doubts or fears, and like them must be 

 ascribed to sudden excitation of brain functions beyond our con- 

 trol from internal causes, the effects of disease. Such acts are not 

 of much interest to the student of psychology, for they do not in- 

 volve a process of thought. They are most commonly observed, 

 however, in persons of the degenerate type which we have been 

 studying. In these persons, then, of degenerate type we observe 

 an imperfect mental equilibrium, which prevents a successful 

 resistance of sudden impulses, and a successful suppression of sud- 

 den doubts and fears, and which thus deprives the victim of his 

 liberty of action in spite of his conscious knowledge that the im- 

 pulses or doubts are absurd or wrong. From time to time in 

 their lives these persons suffer for weeks and months from their 

 mental distress ; then, for unknown reasons, they may be free 

 from it, but usually it returns, and it is an annoyance through the 

 entire life. One of the most interesting studies of the mental pro- 

 cesses of a person thus afflicted has been published by Prof. Royce, 



