CHAPTER 1 



The Systems Concept, and 



Ten Useful Pillars of 

 Mathematical Expression 



In scientific thought we adopt the simplest theory which will explain all 

 the facts under consideration and enable us to explain new facts of the 

 same kind. 



The catch in this criterion lies in the word "simplest. " It is really an 

 aesthetic canon such as we find implicit in our criticisms of poetry or 

 painting. 



The layman finds such a law as 



dx/dt = kd 2 x/dy 2 



much less simple than "It oozes," (or "It diffuses," or "It flows"), of 



which it is the mathematical statement. 



The physicist reverses this judgement, and his statement is certainly the 



more fruitful of the two so far as prediction is concerned. 



(J. B.S. Haldane.) 



THE "SYSTEMS" CONCEPT 



In modern science and engineering an almost unbelievably broad and 

 comprehensive use is made of the term "systems" and its various connota- 

 tions. Chemists have long used the term to indicate the collection of chemi- 

 cals — the chemical system — on which an experimenter was working. Biolo- 

 gists have long used the term to indicate the group of materials and events 



