RELATIONS OF ABNORMAL PSYCHOLOGY 751 



(incompUtude);" 1 and finally there are the phenomena which are 

 characteristic of depression, of diminution of physiological, and 

 especially of psychical functions. In states of excitation one finds 

 the three groups of phenomena occurring in inverse form, the 

 phenomena of agitation disappear, feelings of incompleteness are 

 replaced by feelings of satisfaction, and the physiological and psych- 

 ical functions undergo an elevation. Of these three groups of 

 facts, the third, which is constituted by diminution and augment- 

 ation of function, seems to me to be by far the most important 

 and the most necessary for us to attempt to understand. 



How are we to envisage these transformations which are still far 

 from being understood? It will suffice to summarize them in the 

 form of a general hypothesis which may serve at once to re"sum6 

 a great many facts, to provoke discussion, and to instigate investiga- 

 tion. The phenomena which we have passed in review testify to the 

 fact that the various functions of the nervous system are not all 

 of equal difficulty. Certain functions are more facile than others, 

 and require a lesser amount of nervous energy for the production 

 of their mental phenomena. These functions seem to be arranged 

 in a hierarchy of increasing degrees of difficulty; for when a nerv- 

 ous system loses or regains its strength, its functions disappear 

 or reappear in a regular sequence. The functions which are the 

 first to disappear are evidently the most complex, i. e., those which 

 are concerned with the synthesizing of a great number of sensa- 

 tions and images. We must therefore take account, as has been 

 done particularly in England since the work of Hughlings Jack- 

 son, of the order of development of cerebral centres and cerebral 

 functions. The functions which are the last to be developed in the 

 race and in the individual are evidently the most complex and 

 difficult; they will naturally be most readily affected in fatigue, 

 in sleep, in emotion, and in diseased conditions of the nervous sys- 

 tem. Finally, I believe that these two notions may be united by 

 the introduction of an additional conception. The mental opera- 

 tions which are at once most difficult of accomplishment and most 

 recent in origin are those whose function it is to bring the indi- 

 vidual into relation with the given reality of the moment. They 

 are most complex because reality is in touch with us at so many 

 points, and most recent because the world about us is constantly 

 changing. Evolution is not a thing of the past alone; we are con- 

 stantly called upon to adapt ourselves to new situations, and to 

 evolve new organs and new functions as our animal ancestors did 

 in developing to our present condition. Now, one cap readily see 

 that it is just the adaptation to the present reality, the reaction 

 upon reality, the feeling and enjoyment of reality, which disap- 

 1 Obsessions et psychasthtnie, 1903, 1, p. 264. 



