THE PRESIDENTIAL ADDRESS. 11 



well as bodily? Is it mere analogy to liken the warped attitude of the 

 mind in a psychoneurotic sufferer to the warped attitude of the body 

 constrained by an internal potential pain? Again, some mental events 

 seem spontaneous ; in the nervous system some impulses seem generated 

 automatically from within. 



It may be said of all these similarities of time-relation and the rest 

 between the ways of the nervous system and such simpler ways of 

 mind as I here venture on, that they exist because the operations of 

 the mental part of the nervous system communicate with the exterior 

 only through the non-mental part as gateway — that there, then, the 

 features of the nerve-machinery are impressed on the mind's working. 

 But that suggestion forgets that the higher and more complex the mental 

 process, the longer the time-lag, the more incident the fatigue, the 

 more striking the memory character, and so on. 



Yet all this similarity does but render more succinct the old enigma 

 as to the nexus between nerve impulse and mental event. In the 

 proof that the working of the animal mechanism conforms with the 

 first law of thermodynamics can one say that psychical events are 

 evaluated in the balance sheet drawn up ? And, on the other hand, Mr. 

 Barcro'ft and his fellow-observers in their recent physiological explora- 

 tion of life on the Andes at 14,200 ft. noted that, as well as were their 

 muscles, their arithmetic there was at a disadvantage. The low oxygen 

 pressure militated against both. Indeed we all know that in any of 

 us a few minutes without oxygen, or a few more with chloroform, and 

 the psychical and the nervous events will lapse together. The nexus 

 between the two sets of events is strict. But for comprehension of its 

 nature we still require, it seems, comprehension of the unsolved mystery 

 of the hov/ of hfe itself. A shadowy bridge between them may lie 

 perhaps in the reflection that for the observer himself the physical 

 phenomena he observes are in the last reso)'t psychical. 



The practical man has to accept nervous function as a condition 

 for mental function without breaking his heart over ignorance of their 

 connection. The doctor, the lawyer, and we all, accept it. We know 

 that with structural derangement or destruction of certain parts of the 

 brain goes mental derangement or defect, while derangement or 

 destruction of other parts of the nervous system is not so accompanied. 

 Decade by decade the connection becomes more ascertained between 

 certain mental performances and certain cerebral regions. Certain 

 impairments of ideation as shown by forms of incomprehension of 

 language or of familiar objects can help to diagnose for the surgeon 

 as to what part of the brain a tumour is compressing; and the tumour 

 gone the mental disabilities pass. So, similarly, those who, as Professor 

 Elliott Smith and Sir Arthur Keith, recast the shape of the cerebrum 

 from the cranial remains of prehistoric man can outline for us something 



