We may now proceed to take stock of our present position and briefly to summarise the contents of the foregoing remarks. Many cases of “functional nervous disorder” or “neurosis” exhibit as their most important characteristics symptoms, the underlying factors of which are demonstrably _mental_. A neurosis may be regarded as the failure of an act of adaptation.[45] The resultant mental disturbances do not seriously affect the “reason” or the “intellect” as was formerly supposed, but are in character predominantly instinctive and emotional. The neurotic’s behaviour in the face of an insurmountable difficulty presents a considerable resemblance to that of a child. The reasons why this analogy is not always obvious (though often it is quite plain) is that while in the child one can usually appreciate the cause of the emotional disturbance and watch its progress, these possibilities are often excluded in the case of the civilised neurotic adult. Both his insurmountable difficulty and the historical circumstances which have made it unconquerable may (they do not always) lie within his inmost mental life. Further, the child’s difficulty usually is caused simply by his inability to adjust himself to his environment; or perhaps more often to adjust his environment to himself. The adult neurotic, on the other hand, adds to these difficulties the further significant one of a lack of inner harmony. There are warring elements inside as well as outside him: he is trying to fight the enemy with an army which has mutinied. It follows then that any attempt to restore equilibrium between himself and his social environment must be accompanied by a similar endeavour to bring about his inner harmony. Therefore, in such cases, a certain amount of psychological analysis is indispensable. Without such investigation the application of physical or psychical methods of treatment must inevitably be a shot in the dark.