DESIGN FOR A BRAIN 1/17 



If consciousness is the most fundamental fact of all, why is it 

 not used in this book ? The answer, in my opinion, is that 

 Science deals, and can deal, only with what one man can demon- 

 strate to another. Vivid though consciousness may be to its 

 possessor, there is as yet no method known by which he can 

 demonstrate his experience to another. And until such a method, 

 or its equivalent, is found, the facts of consciousness cannot be 

 used in scientific method. 



The problem 



1/17. It is now time to state the problem. Later, when more 

 exact concepts have been developed, it will be possible to state 

 the problem more precisely (S. 5/14). 



It will be convenient, throughout the discussion, to have some 

 well-known, practical problem to act as type-problem, so that 

 general statements can always be referred to it. I select the 

 following. When a kitten first approaches a fire its reactions are 

 unpredictable and usually inappropriate. It may walk almost 

 into the fire, or it may spit at it, or may dab at it with a paw, 

 or try to sniff at it, or crouch and ' stalk ' it. Later, however, 

 when adult, its reactions are different. It approaches the fire and 

 seats itself at a place where the heat is moderate. If the fire burns 

 low, it moves nearer. If a hot coal falls out, it jumps away. Its 

 behaviour towards the fire is now ' adaptive '. I might have taken 

 as type-problem some experiment published by a psychological 

 laboratory, but the present example has several advantages. It 

 is well known; it is representative of a wide class of important 

 phenomena; and it is not likely to be called in question by the 

 discovery of some small technical flaw. 



We take as basic the assumptions that the organism is mechan- 

 istic in nature, that it is composed of parts, that the behaviour of 

 the whole is the outcome of the compounded actions of the parts, 

 that organisms change their behaviour by learning, and that they 

 change it so that the later behaviour is better adapted to their 

 environment than the earlier. Our problem is, first, to identify 

 the nature of the change which shows as learning, and secondly, 

 to find why such changes should tend to cause better adaptation 

 for the whole organism. 



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