406 ANNUAL REPORT SMITHSONIAN INSTITUTION, 1963 



normally classify as "intelligent," "insightful," "recognitive," "pur- 

 poseful" and so forth — can in principle be shown by an artificial 

 mechanism, embodying only known processes. Some of us are devel- 

 oping ways of enabling such mechanisms to grow and modify parts 

 of tlieir own internal wiring as a result of experience. The design 

 of artificial limbs, speech organs, and mechanisms of visual and audi- 

 tory form-perception are all likely to make rapid progress in the next 

 decade. Many of these and other developments will be linked with 

 prosthetics — the effort to replace human faculties lost by disease or 

 damage. 



This prospect, though (like that of space travel 20 years ago) it 

 may savor of science fiction, inevitably raises two serious questions. 

 The first is whether we are now in a position (in principle — blessed 

 phrase!) to synthesize fully human behavior. The answer, quite 

 shortly, is "no." Those aspects of human behavior that we under- 

 stand well enough to specify exactly can indeed be mechanized, given 

 enough time and space and computer capacity. But mechanization, 

 impracticably complex though it would be, is not the real problem. 

 The fundamental limit to our power of synthesizing human behavior 

 is precisely in our own understanding of what it is to be human. 

 That this is incomplete at present needs no demonstration. That it 

 could ever be otherwise — even in prmciple — I personally take leave 

 to doubt. 



The second question is whether by implication we are now entitled 

 to regard natural human beings as "no more than" cybernetic mecha- 

 nisms. This question is ambiguous. It may be asking whether the 

 human brain-plus-body can be regarded as no more than a cybernetic 

 mechanism. In that case, although our ignorance of brain mecha- 

 nisms still far exceeds our knowledge, most scientists today would, 

 I think, answer with a cautious affirmative. What they would empha- 

 size is the astronomical complexity of any mechanism (whether we 

 call it cybernetic or not) embodying 10,000 million cells, each of which 

 is itself bafflingly complex. 



There is, however, a quite different idea which is so often expressed 

 by asking the same question. This is the fear (or the hope, accord- 

 ing to taste) that a complete cybernetic explanation of human bodily 

 activity, if once we had it, would debunk any higher view of hmnan 

 nature, in moral or religious terms. This idea, I think, is based on a 

 philosophical mistake — the mistaking of these higher accounts of 

 human action and the scientific, mechanistic account as mutually 

 exclusive rivals^ so that if one of them were complete and correct, it 

 would leave no room for the other. The truth seems to be that when 

 theologians speak about moral and religious factors in human behav- 

 ior, they are not talking about quasi-physical (and scientifically 

 inexplicable) forces at work on the mechanism of the brain. They 



