THE REAL WORLD 365 



tion of one rather than another will come to be based more on aes- 

 thetic considerations than on experimental criteria. Once this situation 

 actually exists (rather than potentially as is true at present) it would 

 appear to me obvious that the success of physics would have noth- 

 ing to do with the existence of a hypothetical "real" world. 



Aesthetic considerations in scientific judgment are, of course, not 

 a novelty; and they remain entirely legitimate if, as I suppose, they 

 develop from the larger rational sense indefinitely educable. How- 

 ever, I am here concerned not to combat but rather to welcome 

 Noyes' opinion. Precisely because the situation he describes may rec- 

 ognizably materialize, I can until then meaningfully maintain postu- 

 lates that would be falsified by such an event. 



Second: These postulates, like any others worth considering, dis- 

 charge an explanatory function. Rejecting these postulates, certain 

 data noted hereafter must be either otherwise explained or ignored. 

 But other possible explanations demand other postulates no less 

 numerous and, at least in my opinion, rather less plausible than those 

 I suggest. And the alternate course, of ignoring these data as the 

 phenomenalist customarily does, appears no more satisfactory. The 

 data seem both genuine and germane. Hence, just as we reject a 

 scientific theory that fails to render account of data we conceive a 

 part of "the given" for that theory, I think we must reject a philos- 

 ophy that fails in similar fashion. But what are the data on which 

 this claim is based? They emerge from a systematic review of each of 

 the points earlier raised against naive realism. 



Beyond Inventions— Discoveries! 



Undeniably involving conceptual invention, a physical object testi- 

 fies also to an empirical discovery: the existence of "a compound 

 sensation of relative fixedness." A further discovery: these constructs, 

 which according to Mach "exist only in our understanding," generally 

 behave lawfully. But why should lawful behavior ever occur if a 

 scientific law is, as Mach maintains, nothing but an economic descrip- 

 tion—presumably of "sensations"? The descriptions are no doubt by 

 us invented. But to them corresponds a discovery: economic descrip- 

 tion is possible; and again the question: why or how is it possible? 

 Weizsacker stresses that: 



