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excites it must tend to respond with this one kind of behaviour." McDougall 

 asserts that " this dictum is an arbitrary and wholly baseless assumption and is 

 contradicted by a multitude of facts." Every instance of the operation of what is 

 well named a chain-instinct affords examples. Thus " when a dog chases a rabbit 

 over rough ground, are we to say that an emotion of pursuit selects in turn from 

 among a number of instincts that are organised in its system, running, leaping, 

 yelping, turning to the right or left, halting, sniffing, doubling, or so on ? " Now 

 we may ask, why does the dog yelp and bark ; is it not because there is a pre- 

 organised instinctive sensori-motor mechanism over which its intelligence has not 

 control unless the animal has been trained. The emotional disturbance of the 

 chase is so strong that it excites the subcortical preorganised reflex mechanism of 

 vocalisation which has become structurally organised in the long procession of 

 ages when the dog hunted in packs. Here undoubtedly the instinct has only one 

 kind of behaviour although in many instances it may be to its advantage when it 

 is hunting singly. 



Mr. Shand is not a physiologist, and accordingly in this otherwise admirable 

 work he has neglected the teachings of physiology. While it must be admitted 

 that physiologists have only lifted a corner of the impenetrable veil which hides 

 the mysteries of the Science of Mind, nevertheless great advances have been made 

 since Maudsley forty years ago advocated the importance of physiology in the 

 " Method of the Study of Mind " in the following passage, p. 48, Mental Physiology. 

 ' The past history of Psychology — its instructive progress so to speak — no less than 

 the consideration of its present state proves the necessity of admitting the objective 

 method of the Study of Mind. That which a just reflection teaches incontestably, 

 the present state of Physiology illustrates practically. Though very imperfect as 

 a Science, Physiology has made sufficient progress to prove that no Psychology 

 can endure except it be based upon its investigations." I, however, am in thorough 

 agreement with the further statement of Maudsley. " No one pretends that 

 Physiology can for many years to come furnish the complete data of a positive 

 mental science." Still Physiology has made notable advances and in no direction 

 more than in the bio-chemistry of the ductless glands and the influence of their 

 internal secretions on mental and bodily functions in health and disease. This 

 knowledge therefore cannot be neglected in any consideration of the foundations 

 of character, for as Bacon says : " not only the characters and dispositions 

 impressed by nature should be received into this treatise, but those alone which 

 are impressed upon the mind by sex, age, country, state of health, make of 

 body, etc." 



It will not be out of place to further consider the question of Instincts and 

 Emotions in the light of modern physiological knowledge ; for it will probably 

 appeal to the readers of SCIENCE PROGRESS, however elementary and imperfect it 

 may be in solving the problems under consideration, if the knowledge so acquired 

 rests upon the sure basis of direct observation. 



Some Physiological Aspects of the Question of Instincts 



and Emotion 



Mr. McDougall finds fault with Mr. Shand for saying that the appetite for 

 food in the new-born infant is aroused by internal rather than external stimu- 

 lation, which is the feeling or impulse which accompanies or controls the search 

 for and absorption of food ; but neither Mr. Shand nor his critics have paid 

 any attention to the important advances made in our knowledge of biochemical 

 stimuli, the result of internal secretions or hormones in the preservation of the 



