When dangers known are compared with dangers obscure or unknown—and perceived to be unknowable—the fear of the unknown often prevails against the fear of the known, and we prefer with Hamlet to fear the ills we have than fly to others we know not of. I must in conclusion express my conviction that while the physiological and objective study of fear and other emotions is of very considerable value, yet it is only introspective analysis which can reveal the true nature and genesis of fear and all emotion. What fear is and what is the process of its development can only be determined by the direct study of consciousness as a life factor in the struggle for existence. This I attempt in the present chapter, with the main result that fear, as indeed every emotion, does not consist of pain or cognition-revivals in any form, but is a feeling reaction from the representation of the feeling potency of the object. CHAPTER VIII _THE DIFFERENTIATION OF FEAR_ Fear, according to the analysis we have made, includes representation of object in its feeling value, predominant tone of mental pain, and will recoil. Fear in its primitive form, as we have seen, was a sudden and transitory phenomenon in consciousness, a simple thrill of feeling awaking will to spasmodic violent effort in the struggle for existence. All states of fear in early psychical history were practically alike in quantity, quality and intensity. Every fear is like every other fear in its pain tone and will effort. Every object and event considered as painful is equally feared; there is no distinction of more or less fear, nor any qualitative differentiation. Very young children manifest equal fear disturbance and seemingly identical in nature on all fearful occasions. Prospect of vaccination, of a scratch, of the pulling of a tooth, of a whipping, of an amputation, produce equally paroxysms of fear, waves of painful emotion, which discharge themselves in muscular contortions. The lowest animals likewise appear in all cases frightened to the same degree and in the same way. It must be said, however, that this period of simple undifferentiated fear is undoubtedly very brief, and embraces in the individual and the race but a comparatively small number of phenomena; but a careful study, even by the method of approximation will, I believe, show it to be a definite initial phase.