246 ANNUAL REPORT SMITHSONIAN INSTITUTION, 1954 



tion of America built us a machine that recognizes the individual 

 letters of a printed alphabet and calls them off vocally. Another less 

 serious engineer made a mechanical bug that knows when it is hungry 

 for more juice in its little battery, trots off to the proper socket, con- 

 nects itself and gets a recharge. If there is radio interference in the 

 neighborhood, I suppose the gadget might develop a simple sort of 

 nervous prostration like Professor Liddell's sheep and goats. 



This jest of mine reflects the feeling of conservative anatomists and 

 physiologists that cybernetic concepts fall far short of explaining the 

 workings of the nervous system, partly, I admit, because we have by 

 no means worked out a complete description of the animal machine 

 for engineers to imitate. There are a lot of circuits and connections 

 still to be traced. Yet the parallel onward march of neurology, bio- 

 physics, and electronic engineering makes it probable that all the 

 operations of the animal mind result from the flow of electrical charges, 

 that is to say, the transfer of ions in the cells of the body. When an 

 experimenter produces neurosis in the sheep, or (to take a more agree- 

 able example) when a hunting dog is conditioned to stand and point 

 to a pheasant, I have no difficulty in supposing that the whole condi- 

 tioning process occurs entirely on the material level. If asked whether 

 I suppose this to be true also of more complex mental performances 

 involving intricate choice of alternatives on the basis of a large stock 

 of stored information, say, a fullback running through a broken field 

 or Shakespeare writing a sonnet, I have to say I do not know. Even 

 what I just said about the hunting dog is a hypothesis. We biologists 

 are bound to work on such hypotheses, even if we do not expect that 

 a good sonnet will ever be written by a man-made machine. 



But suppose, just for the argument, that it is so, that all the higher 

 activities of the mind — all that raises man above the unreflective beast 

 and leads him to create arts, sciences, and humane learning — suppose 

 that this is entirely the result of ionic shifts in our cells for which we 

 may some day calculate the equations : what then ? Do we scrap our 

 libraries and colleges? Is my humanist friend whose question started 

 me on this essay to discontinue teaching the history of literature and 

 philosophy ? 



What I now reply is not the utterance of mystics or metaphysicians ; 

 it is the word of the histologist looking up from his microscope, the 

 physiologist from his oscillograph. We see that the human thinking 

 mechanism, if it is a mechanism, is utterly complex and multifariously 

 sensitive beyond any conceivable instrument of metal and glass, and 

 therefore its individual reactions will always be in large part un- 

 predictable. Let me reinforce this statement by quoting again Karl 

 Lashley, one of the most thoughtful of o\ir neuropsychological experi- 

 menters. In this essay on the mechanism of learning, he writes : 



