=Thresholds and Sensations.= The importance of these principles is obvious. The next chapter will show more of their influence on ideas and emotions; but for the present we will consider their lessons in the sphere of the physical. Psychology speaks here in no uncertain terms to physiology. Whoever becomes fascinated by the processes of his own body is bound to magnify the sensations from those processes, until the most insignificant message from the subconscious becomes a distressing and alarming symptom. The person whose mental ear is strained to catch every little creaking of his internal machinery can always hear some kind of rumble. If he deliberately lowers his thresholds to the whole class of stimuli pertaining to himself, there is small wonder that they sweep over the boundaries into consciousness with irresistible force. =The Motives for Sensitiveness.= Sensitiveness is largely a matter of choice, but what determines choice? Why is it that one person chooses altruism as the master threshold that determines the level of all the others, while another person who ought to be equally fine lowers his thresholds only to himself? What makes a person too interested in his own sensations and feelings? As usual there is a cause. The real cause back of most cases of chronic sensitiveness is an abnormal desire for attention. Sometimes this love of attention arises from an under-developed instinct of self-assertion, or "inferiority complex." If there is a sense of inadequacy, a feeling of not being so important as other people, a person is quite likely to over-compensate by making himself seem important to himself and to others in the only way he knows. All unconsciously he develops an extreme sensitiveness which somehow heightens his self-regard by making him believe himself finely and delicately organized, and by securing the notice of his associates. Or, again, the love of attention may be simply a sign of arrested development, a fixation of the Narcissistic period of childhood which loves to look at itself and make the world look. Or there may be lack of satisfaction of the normal adult love-life, a lack of the love and attention which the love-instinct naturally craves. If this instinct is not getting normal outlet, either directly through personal relationships or indirectly through a sublimated activity, what is more natural than that it should turn in on itself, dissociate its interest in other things and occupy itself with its own feelings, and at the same time secure the coveted attention through physical disability, with its necessity for special ministration?