REGULATING THE VERY LARGE SYSTEM 13/12 



It will be noticed that the concepts of design or construction are 

 essentially applicable to sets, in spite of the common linguistic use 

 of the singular. (Compare S.7I3.) Thus "the gene-pattern deter- 

 mines the form of the heart" is a shorthand way of saying that 

 elements in the set of gene-patterns among different species can be 

 put into correspondence with those in the set of possible hearts in 

 the various species, like the wires at the two ends of a telephone 

 cable. Thus the act of ''designing" or "making" a machine is 

 essentially an act of communication from Maker to Made, and the 

 principles of communication theory apply to it. In particular the 

 measures that were developed for treating the case in which various 

 possible messages are reduced to one message can now be applied 

 to the case when various possible machines are reduced to one 

 machine. 



A useful conceptual device for forcing this aspect into prominence 

 is to imagine that the act of designing has to take place through the 

 telephone, or by some other specific channel. The quantities of 

 variety can then readily be identified by identification of the actual 

 quantity of information that will have to be transmitted. 



13/12. When a designer selects the final form of the machine, what 

 does "selecting" the machine mean in terms of the general concepts 

 of this book? Consider the following sequence of examples, in 

 which the final machine is a radio receiver. 



The first is the case of the buyer who has three machines before 

 him, and he selects one. The second case, equivalent to the first 

 from the abstract point of view, occurs when the designer of a radio 

 set, wavering between three possible circuits, finally selects one. 

 The third case, abstractly equivalent to the previous two, occurs 

 when the owner of a radio set that has three circuits built into it, 

 moves a switch to one of three positions and thereby selects which 

 circuit shall actually be used. Thus, from the abstract point of 

 view, selecting one machine from three is equivalent to selecting 

 one value from three at a parameter. For example, suppose the 

 choice is to be between the three machines a, j8, and y (each on the 

 states a and b); 



. a b ^ , a b . a b 



a:\ ^:| y:| 



b a a a b b 



Suppose ^ is selected and the selector finishes with the machine 



I a b 



Y 



a a 

 253 



