11/13 AN INTRODUCTION TO CYBERNETICS 



If I am not misinterpreting him, his concepts and those used here are 

 equivalent thus : 



Coenetic variable (CVq) <-> Disturbance (D) 

 Response (R,) <-^ Response (R) 

 Environmental circumstances (E,) *^ Table (T) 



Subsequent occurrence (G,J *^ Outcome (E) 



A reading of his book may thus help to extend much of the theory 

 given in this Part, for he discusses the subject extensively. 



11/13. The law now enables us to see the relations existing between 

 the various types of variety and information that affect the living 

 organism. 



A species continues to exist (S.10/4) primarily because its members 

 can block the flow of variety (thought of as disturbance) to the gene- 

 pattern (S.10/6), and this blockage is the species' most fundamental 

 need. Natural selection has shown the advantage to be gained by 

 taking a large amount of variety (as information) partly into the 

 system (so that it does not reach the gene-pattern) and then using 

 this information so that the flow via R blocks the flow through 

 the environment T. 



This point of view enables us to resolve what might at first seem 

 a paradox — that the higher organisms have sensitive skins, responsive 

 nervous systems, and often an instinct that impels them, in play or 

 curiosity, to bring more variety to the system than is immediately 

 necessary. Would not their chance of survival be improved by an 

 avoidance of this variety ? 



The discussion in this chapter has shown that variety (whether 

 information or disturbance) comes to the organism in two forms. 

 There is that which threatens the survival of the gene-pattern — the 

 direct transmission by T from D to E. This part must be blocked 

 at all costs. And there is that which, while it may threaten the 

 gene-pattern, can be transformed (or re-coded) through the regulator 

 R and used to block the effect of the remainder (in T). This infor- 

 mation is useful, and should (if the regulator can be provided) be 

 made as large as possible; for, by the law of Requisite Variety, the 

 amount of disturbance that reaches the gene-pattern can be dimin- 

 ished only by the amount of information so transmitted. That is 

 the importance of the law in biology. 



It is also of importance to us as we make our way towards the last 

 chapter. In its elementary forms the law is intuitively obvious and 

 hardly deserving statement. If, for instance, a press photographer 



212 



