CHAPTER IX 



The Evolutmi 

 of Scientific Theories 



HE MOST impressive features on 

 the skyline of science are its great theories. "Science has its cathe- 

 drals, " say Lewis and Randall, "built by the eflForts of a few archi- 

 tects and of many workers." But those cathedrals prove sadly mu- 

 table. Most of the oldest structures have fallen into decay. Even 

 much newer edifices have not remained intact; and some have been 

 moved bodily to new foundations, where they become wings of still 

 greater structures. The continuous turmoil of construction and re- 

 construction may well repel the nonscientific onlooker. Wishing to 

 see theoretic construction rendered enduring, he would hope to see 

 theories subjected to definitive and final proof. But this possibility 

 simply does not exist. 



Consider the logical constellation. A scientific theory is constituted, 

 we saw, by the affiliation of a model ( M ) and a formalism ( F ) , only 

 one of which may be wholly explicit. Pro\dsionally accepting some 

 theory (MF), I derive from it a multitude of colligative relations, 

 as shown in this schema: 



li (MF), then A(x,a,r),B{ij, by), C{z,Cz), ... 



I represent a typical colligative relation as A{x,aj) to indicate that, 

 given specification of certain initial and/or boundary conditions, x, 

 the relation A permits prediction of one or more observable condi- 



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