All these abnormal forms of expression, de lusions, hallucinations, obsessions, compulsions are then efforts at expression of certain instinc tive tendencies which are not acceptable to the individual. They represent indulgences that at some past period were normal to the individual, that is, they are relatively infantile. The in dividual who flies into a rage and curses and kicks the inanimate objects of his environment, breaks furniture and tears up books, is acting like a small child that has been thwarted in some of its desires. All the other abnormal reactions could be explained in a similar way so that we might say that the abnormal as a class are not yet fully grown in some aspect of their personality, they retain infantile traits of character. This is obvious in the idiots and imbeciles but less obvious as we have to deal with better developed personalities. This ex planation, however, becomes again obvious in those very dilapidated types of chronic mental illness that degenerate into helplessness, who wet and soil themselves as do infants and have to be fed and otherwise cared for just like children. Mental disease, therefore, shows re actions that reproduce types of response that were at one time normal either in the history of the individual —infancy and childhood— or in the history of the race-primitive matt and from this point of view their study has been termed paleopsychology.
There are two ways of reacting to these inherent difficulties— conflicts — of instinctive expression either by turning back within ones self and reanimating infantile ways of react ing — the method of introversion — or by run ning away from the difficulty, so to speak, into reality and by developing a great activity and interest in everything about and so attempting to escape a reckoning with onesself — the method of extroversion. The first is, in gen
eral, the more serious type and in it we find the malign types of the psychosis such as de mentia precox : the second is less serious and here we find the more benign types such as the manic-depressive psychosis. A chronic delu sional psychosis such as paranoia represents a more or less permanent compromise which is not as disintegrating as the first nor as recover able as the second.
All these methods of reacting are found equally among the relatively normal; the only differences are differences of more or less. In mental disease we find the mechanisms of normal mental life writ large because dispro portionately emphasized in some direction. The symptoms of mental disease can thus be under stood as the outward evidences of attempts at adjustment, made difficult by some psychologi cal conflict and the language of the symptom, so to speak, can be translated when it is under stood as expressing reactions of escape, de fense or compromise in the face of the problem presented. The study of these exaggerated forms of reaction found in the mentally ill has gone a long way to help explain the psychology of the normal because the failures represent an experiment of nature, so to speak, which throws certain of the aspects of the personality into relief. A complicated mechanism comes to be understood when it gets out of order and finally by taking it apart.