250 Mr. Vidor Horsley [March 27, 



WEEKLY EVENING MEETING, 



Friday, March 27, 1885. 



Sir Frederick Bramwell, F.E.S. Manager and Vice-President, 

 in the Chair. 



Victor Horsley, Esq. F.E.C.S. 



The Motor Centres of the Brain, and the Mechanism of the Will. 



Feeling deei)ly as I do the responsibility I have incurred in under- 

 taking to address you to-night, I desire to express my regret that I 

 cannot instead share with you the pleasure of listening to the dis- 

 tinf^uished man who has been prevented by a most painful bereave- 

 ment from addressing you to-night. 



My subject being the mechanism of the will, it might be asked, 

 " What has a surgeon to do with psychology ? " To which I would 

 answer, " Everything." For without sheltering myself behind Mr. 

 Jonachan Hutchinson's trite saying that "a surgeon should be a 

 physician who knows how to use his hands," I would remind you that 

 pure science has proved so good a foster-mother to surgery, that diseases 

 of the brain which were formerly considered to be hopeless, are now 

 brought within a measurable distance of the knife, and therefore a 

 step nearer towards cure. Again, I would remind you that surgeons 

 rather than physicians see the experiments which so-called Nature is 

 always providing for us, — experiments which, though horribly clumsy, 

 do on rare occasions, as I shall presently show you to-night, lend us 

 powerful aid in attempting to solve the most obscure problems ever 

 presented to the scientist. 



The title I have chosen may possibly be objected to as too com- 

 prehensive ; but until we are ready to admit a new terminology wo 

 must employ the old in order to convey our meaning intelligibly, 

 although there may be coupled therewith the risk of exjjressing more 

 than we desire. Thus when I speak of the mechanism of the will 

 and the motor centres of the brain, I do not intend (as indeed must 

 be obvious) to discuss the existence of the so-called freedom of the 

 will, or the source of our consciousness of voluntary power. 



I shall rather describe to you first the general plan of the 

 mechanism which convoys information to our biain, the thinking 

 ort^an • next the arrangement of those parts in it which are concerned 

 wi'tli voluntary phenomena; and finally I shall seek to show by 

 means of experiment that tlie consciousness of our existing as single 

 beings, the consciousness of our possessing but one will as people 

 say, wliile at the same time we know that we possess a double nervous 



