Abnormal Psychology

will be devoted principally to the abnormal aspects of the emotions, yet it will be necessary to give a summary of the various theories of normal emotional processes, to which will be added the more recent experimental researches on the question, such as the electrical phenomena (the psycho-galvanic reflex) and a modification of these phenomena, namely, the pulse reaction tests. Like sleep, the emotions are instinctive and are inseparable from our everyday psychic existence. As a preliminary, there can be applied to the emotions the same important question as can be applied to sleep, namely, at what step in evolution did the emotions first appear? This question is more easily propounded than answered,for the emotions are very complex phenomena and enter into all the phases of our everyday existence. In animals, possessing a well- organized nervous system, well-marked emotional expressions occur, yet these seem to be absent from the lower organisms, in which the nervous system is either entirely absent or is limited to a mere collection of ganglion cells. If this be true, then the manifestations of the emotions must have arisen at some phase of natural selection and possibly the physical expressions of certain emotions were a strong factor in the early struggles for existence. Since emotional expressions require a certain active state of consciousness, it may be said in general, although, of course, this statement is open to certain modifications and corrections, ...