While health cannot be separated from disease by a sharp line, the two are relative and fluctuating. Still, on the whole, the two can be differentiated by the criterion of hurt and dissolution. Any process or state conducive to hurt, and tending to dissolution of the organism may be regarded as pathological or abnormal. The same criterion should be applied, when differentiating the healthy, normal states of instincts and emotions from abnormal and morbid states of instinctive and emotional activities. Those states that further life activities are healthy, normal; those that hinder life are morbid.
The same holds true of the fear instinct. Every form of fear which, instead of helping or furthering vigor of life, instead of stimulating living energy, instead of being a protection, becomes a hindrance, a menace to the organism, is accompanied with suffering and distress, and ultimately leads to destruction, should be regarded as essentially morbid.
The following are the chief characteristics of morbid instinctive and emotional states:
I. When they are disproportionate to the cause.
II. When they are chronic.
III. When their feeling-tone is painful, distressing.
IV. When they are non-adaptive to the stimulations.
V. When the reactions are not adjusted to the external environment.
VI. When they are uncontrollable.