THE REAL WORLD 373 



deavor to carry through the program of classical physics, Heisenberg 

 calls attention to 



calls attention to 



. . . the completely unexpected realization that a consistent pursuit 

 of classical physics forces a transfoi*mation in the very basis of this 

 physics, . . . 



On the basis of many such occurrences, Einstein concludes that: 



The historical development has shown that among the imaginable 

 theoretical constructions there is invariably one that proves to be 

 unquestionably superior to all others. Nobody who really goes into 

 the matter will deny that the world of perceptions determines the 

 theoretical system in a virtually unambiguous manner, although no 

 logical way leads to the principles of the theory. 



The burden of proof lies with any who would deny this conclusion. 

 Leaving open to them any and all means short of the inane expedient 

 of dismissing the bulk of our experience as hallucinatory, let them 

 be challenged to produce some reconstruction of, say, modern physi- 

 cal theory which attains as high a correlative index as that already 

 achieved. 



We saw in Chapter IX that an entire complex of laws and theories 

 is involved in any comparison of hypothesis and experiment— just as 

 Duhem maintained. 



. . . hypotheses shall be chosen in such a manner that from them 

 taken as a tvhole mathematical deduction may draw consequences 

 representing with a sufficient degree of approximation the totality 

 of experimental laws. . . . The two systems must be taken in their 

 integrity: the entire system of theoretical representations on the one 

 hand, and the entire system of observed data on the other. As such 

 they are to be compared to each other and their resemblance judged. 



Thus a mismatch between theoretic prediction and experimental 

 finding can always be repaired by making a change anywhere in the 

 theoretic constellation. But, just because a large theoretic system is 

 involved in all such comparisons, each change has potentially some 

 effect everywhere. In the long term we find that, though there are 

 numberless ways of "saving" any theoretic statement or group of 

 statements, there is one theoretic constellation superior in correlative 

 index to any others we have conceived. 



The involvement of a large theoretic constellation in any and all 



