186 SECTIONAL ADDRESSES. 



that variations in the actions of drugs on different persons may have their 

 basis in deep-seated physiological variations, and I believe that the 

 study of tliese variations of susceptibility may do more than perhaps 

 any other line of work to enable us to understand the nature of temjjera- 

 ment and the relation between the mental and physical characters which 

 form its two aspects.' 



Elvers 's interests did not lie in the collection of masses of hetero- 

 geneous data, in obtaining blurred averages from vast numbers of 

 individuals, in concocting mathematical devices, or in applying mathe- 

 matical formulae to the numerical data thus accumulated; they lay 

 throughout his varied career in studying and analysing individual mental 

 differences, in getting tO' know the individual in his I'elation to his 

 environment. In ordinary circumstances, as he later said, ' There is 

 too little scope for the variations of conditions which is the essence of 

 experiment. . . . While the experimental method as applied to the 

 normal adult has borne little fruit, it would be difficult to rate^too 

 highly the importance of experiment in discovering and testing methods 

 to be used in other lines of psychological inquiry where a wider variation 

 of conditions is present ' (Brit. J. of Psychol., vol. x., p. 185). 



It was the importance ol studying the play of the most variable 

 conditions that led Rivers to investigate, as we have seen, first racial 

 mental differences, then the differences produced in a given individual 

 by nerve section, and finally those produced in different individuals by 

 different dnigs. Throughout his life he was steadfast to the biolo'gical 

 standpoint, correlating the psycholo^gical with the physiological, and 

 hoping to discover different mental levels coiTesponcling tO' different 

 neural levels. 



And so we approach the last phase of Rivers 's psychological work, 

 the outcome ol his war experiences. In 1907 he had given up his 

 University teaching in experimental psychology ; for six years before the 

 war he had published nothing O'f psychological or physiological interest. 

 This was a period in which Rivers devoted himself wholly to the 

 ethnology and sociology of primitive peoples. The outbreak of war 

 found him for the. second time visiting Melanesia for ethnological field 

 work. Failing at first to get war work on his return to England, Rivers 

 set himself to' prepare the Fitzpatrick Lectures on ' Medicine, Ma,gic 

 and Religion,' which he had been invited to deliver to the Royal College 

 ol Physicians of London in 1915 and r916. In 1915 his psychological 

 and ethnological researches were recognised by the award 'to him of a 

 Royal Medal by the Royal Society, of which he had been elected a 

 Fellow in 1908. In July" 19 15 he went as medical officer to the Maghull 

 War Hospital, near Liverpool, and in 1916 to the Craiglockhart War 

 Hospital, Edinburgh, receiving a. commission in the R.A.M.C. In 

 these hospitals he began the work on the psychoneuroses that led him 

 to his studies of the unconscious and of dreams, which resulted in 

 his well-known book, ' Instinct and the Unconscious,' pubUshed first in 

 1920 (already in a second edition), and in a. practically completed volume 

 on ' Conflict and Dream,' wliich is to be published posthumously. From 

 1917 he acted as consulting psychologist to the Royal Air Force, being- 

 attached to the Central Hospital at Hampstead. 



