360 THE BEAL WORLD 



Consider, finally— is not the whole quest for intelligibility obviously 

 absurd? We saw in Chapters III and VIII that scientific explanation 

 can never be complete. The postulates of our ultimate theory are not 

 themselves explained. Einstein leaves as unexplained the constancy 

 of the velocity of light, as Darwin leaves the origin of the variations 

 sifted by natural selection, as Newton leaves the origin and mode of 

 action of a universal gravitational force. "Natural science," says 

 Mach, 



. . . has to resolve the more complicated facts into as few and as 

 simple ones as possible. This we call explaining. These simplest facts, 

 to which we reduce the more complicated ones, are always unintelli- 

 gible in themselves, that is to say, they are not further resolvable. . . . 



. . . People usually deceive themselves in thinking that they have 

 reduced the unintelligible to the intelligible. Understanding consists 

 in analysis alone; and people usually reduce uncommon unintelli- 

 gibilities to common ones. ... 



What facts one will allow to rank as fundamental facts, at which 

 one rests, depends on custom and history. 



Given custom Kant found self-evident the universal force Leibniz 

 had found absurd and which we, with a further history, again come 

 to query. 



Common acceptance does not render the "fundamental facts" any 

 less unintelligible. Thermodynamics is a theory exemplary for the 

 small number of its ultimate unintelligibilities, and Bridgman writes: 



The first law of thermodynamics properly understood is not at all a 

 statement that energy is conserved, for the energy concept without 

 conservation is meaningless. The essence of the first law is contained 

 in the statement that the energy concept exists . . . 



But as such the concept "exists" only in our minds— and there in no 

 very clear form since, as Bridgman adds, "no general meaning can 

 be given to the energy concept, but only specific meanings in special 

 cases." Moreover, the rise of quantum mechanics poses a still sterner 

 challenge to the whole idea of intelligibility. Can we pretend to com- 

 prehend "particles" that "jump" from state to state without inter- 

 mediary "existence," "particles" the number of which "actually pres- 

 ent" depends on how closely the system is observed, "particles" that 

 are at other times "waves," and so on? Given such as these, the naive 



